diff --git a/apps/framework-editor/app/components/table/EditableCell.test.tsx b/apps/framework-editor/app/components/table/EditableCell.test.tsx
index cb527f94c..e04f032b7 100644
--- a/apps/framework-editor/app/components/table/EditableCell.test.tsx
+++ b/apps/framework-editor/app/components/table/EditableCell.test.tsx
@@ -1,6 +1,7 @@
 import { fireEvent, render, screen } from '@testing-library/react';
 import { beforeEach, describe, expect, it, vi } from 'vitest';
 import { EditableCell } from './EditableCell';
+import { clearEditorSize, saveEditorSize } from './editor-size-storage';
 
 // The ui package ships untranspiled JSX in dist; stub the bits the cell uses.
 vi.mock('@trycompai/ui', () => ({
@@ -55,7 +56,10 @@ describe('EditableCell — non-expandable (default)', () => {
 });
 
 describe('EditableCell — expandable', () => {
-  beforeEach(() => vi.clearAllMocks());
+  beforeEach(() => {
+    vi.clearAllMocks();
+    clearEditorSize();
+  });
 
   it('shows an expand affordance', () => {
     setup({ expandable: true });
@@ -139,4 +143,13 @@ describe('EditableCell — expandable', () => {
     fireEvent.click(screen.getByRole('button', { name: 'Cancel' }));
     expect(onExpandedChange).toHaveBeenLastCalledWith(false);
   });
+
+  it('reopens the editor at the persisted size (FRAME-3)', () => {
+    saveEditorSize({ width: 900, height: 500 });
+    setup({ expandable: true });
+    fireEvent.click(screen.getByRole('button', { name: /large editor/i }));
+    const textarea = screen.getByRole('textbox') as HTMLTextAreaElement;
+    expect(textarea.style.width).toBe('900px');
+    expect(textarea.style.height).toBe('500px');
+  });
 });
diff --git a/apps/framework-editor/app/components/table/EditableCell.tsx b/apps/framework-editor/app/components/table/EditableCell.tsx
index 26464cdad..02204891f 100644
--- a/apps/framework-editor/app/components/table/EditableCell.tsx
+++ b/apps/framework-editor/app/components/table/EditableCell.tsx
@@ -10,7 +10,8 @@ import {
   Textarea,
 } from '@trycompai/ui';
 import { Maximize2 } from 'lucide-react';
-import { useState } from 'react';
+import { useRef, useState } from 'react';
+import { loadEditorSize, saveEditorSize, type EditorSize } from './editor-size-storage';
 
 interface EditableCellProps {
   value: string | null;
@@ -44,6 +45,10 @@ export function EditableCell({
   const [editValue, setEditValue] = useState(value ?? '');
   const [isExpanded, setIsExpanded] = useState(false);
   const [expandValue, setExpandValue] = useState(value ?? '');
+  // Remembered editor size (FRAME-3): the large editor is resizable in both
+  // directions and reopens at the size the user last left it.
+  const [editorSize, setEditorSize] = useState<EditorSize | null>(null);
+  const textareaRef = useRef<HTMLTextAreaElement>(null);
 
   // Keep local open state and the parent notification in lockstep so the row
   // highlight tracks the dialog exactly (open icon, right-click, save, cancel,
@@ -78,6 +83,7 @@ export function EditableCell({
   const handleOpenExpanded = () => {
     if (disabled) return;
     setExpandValue(value ?? '');
+    setEditorSize(loadEditorSize());
     setExpanded(true);
   };
 
@@ -88,6 +94,19 @@ export function EditableCell({
     setExpanded(false);
   };
 
+  // Persist the editor size after a resize-handle drag (fires on pointer
+  // release). Skipped when unchanged so plain clicks don't thrash storage.
+  const handleEditorResizeEnd = () => {
+    const el = textareaRef.current;
+    if (!el) return;
+    const next: EditorSize = { width: el.offsetWidth, height: el.offsetHeight };
+    if (editorSize && next.width === editorSize.width && next.height === editorSize.height) {
+      return;
+    }
+    setEditorSize(next);
+    saveEditorSize(next);
+  };
+
   if (disabled) {
     return (
       <span className="text-muted-foreground block truncate px-2 py-1.5 text-sm">
@@ -149,15 +168,22 @@ export function EditableCell({
       </button>
 
       <Dialog open={isExpanded} onOpenChange={setExpanded}>
-        <DialogContent className="sm:max-w-[760px]">
+        <DialogContent className="max-h-[95vh] w-fit max-w-[95vw] overflow-y-auto sm:max-w-[95vw]">
           <DialogHeader>
             <DialogTitle>{expandTitle}</DialogTitle>
           </DialogHeader>
           <Textarea
+            ref={textareaRef}
             value={expandValue}
             onChange={(e) => setExpandValue(e.target.value)}
+            onMouseUp={handleEditorResizeEnd}
             autoFocus
-            className="min-h-[260px] font-mono text-sm"
+            className="max-h-[80vh] max-w-[92vw] min-h-[260px] min-w-[320px] resize font-mono text-sm"
+            style={
+              editorSize
+                ? { width: editorSize.width, height: editorSize.height }
+                : { width: 680 }
+            }
           />
           <DialogFooter>
             <Button variant="outline" onClick={() => setExpanded(false)}>
diff --git a/apps/framework-editor/app/components/table/editor-size-storage.test.ts b/apps/framework-editor/app/components/table/editor-size-storage.test.ts
new file mode 100644
index 000000000..25994f6b6
--- /dev/null
+++ b/apps/framework-editor/app/components/table/editor-size-storage.test.ts
@@ -0,0 +1,35 @@
+// @vitest-environment jsdom
+import { afterEach, describe, expect, it } from 'vitest';
+import { clearEditorSize, loadEditorSize, saveEditorSize } from './editor-size-storage';
+
+const COOKIE_NAME = 'fwk-editor-expand-editor-size';
+
+function setRawCookie(value: string) {
+  document.cookie = `${COOKIE_NAME}=${encodeURIComponent(value)}; path=/`;
+}
+
+describe('editor-size-storage', () => {
+  afterEach(() => clearEditorSize());
+
+  it('returns null when nothing is stored', () => {
+    expect(loadEditorSize()).toBeNull();
+  });
+
+  it('round-trips a valid size', () => {
+    saveEditorSize({ width: 900, height: 500 });
+    expect(loadEditorSize()).toEqual({ width: 900, height: 500 });
+  });
+
+  it('returns null for malformed JSON', () => {
+    setRawCookie('{not json');
+    expect(loadEditorSize()).toBeNull();
+  });
+
+  it('does not store non-positive or non-numeric dimensions', () => {
+    saveEditorSize({ width: 0, height: 100 });
+    expect(loadEditorSize()).toBeNull();
+
+    setRawCookie(JSON.stringify({ width: 'x', height: 1 }));
+    expect(loadEditorSize()).toBeNull();
+  });
+});
diff --git a/apps/framework-editor/app/components/table/editor-size-storage.ts b/apps/framework-editor/app/components/table/editor-size-storage.ts
new file mode 100644
index 000000000..f1a751246
--- /dev/null
+++ b/apps/framework-editor/app/components/table/editor-size-storage.ts
@@ -0,0 +1,60 @@
+/**
+ * Persisted size for the large multi-line cell editor (FRAME-3). The user can
+ * resize the editor in both directions; we remember the last size so the next
+ * open reuses it. Stored in a cookie (per the ticket), survives reloads.
+ */
+export interface EditorSize {
+  width: number;
+  height: number;
+}
+
+const COOKIE_NAME = 'fwk-editor-expand-editor-size';
+const ONE_YEAR_SECONDS = 60 * 60 * 24 * 365;
+
+function isValidSize(value: unknown): value is EditorSize {
+  if (typeof value !== 'object' || value === null) return false;
+  const { width, height } = value as Record<string, unknown>;
+  return (
+    typeof width === 'number' &&
+    typeof height === 'number' &&
+    Number.isFinite(width) &&
+    Number.isFinite(height) &&
+    width > 0 &&
+    height > 0
+  );
+}
+
+function readCookie(name: string): string | null {
+  const match = document.cookie
+    .split('; ')
+    .find((row) => row.startsWith(`${name}=`));
+  return match ? match.slice(name.length + 1) : null;
+}
+
+export function loadEditorSize(): EditorSize | null {
+  if (typeof document === 'undefined') return null;
+  try {
+    const raw = readCookie(COOKIE_NAME);
+    if (!raw) return null;
+    const parsed: unknown = JSON.parse(decodeURIComponent(raw));
+    return isValidSize(parsed) ? parsed : null;
+  } catch {
+    return null;
+  }
+}
+
+export function saveEditorSize(size: EditorSize): void {
+  if (typeof document === 'undefined') return;
+  if (!isValidSize(size)) return;
+  try {
+    const value = encodeURIComponent(JSON.stringify(size));
+    document.cookie = `${COOKIE_NAME}=${value}; path=/; max-age=${ONE_YEAR_SECONDS}; samesite=lax`;
+  } catch {
+    // Ignore — resizing still works in-session even if the cookie can't be set.
+  }
+}
+
+export function clearEditorSize(): void {
+  if (typeof document === 'undefined') return;
+  document.cookie = `${COOKIE_NAME}=; path=/; max-age=0; samesite=lax`;
+}