Growable grid dimensions

What it does

The grid used to be a fixed 100 rows × 26 columns. The engine underneath is sparse (no dimension limit), so anything written past that rectangle — an imported CSV with more than 100 rows or more than 26 columns, a large paste — was stored but unreachable: you couldn't see it, scroll to it, or select it.

Now the grid grows to fit its content. Its extent is derived from the active sheet: the larger of the compact default, the furthest cell that carries content, and wherever the cursor currently is. It's recomputed on every change — an edit, a paste, an import, undo/redo, a sheet switch, and a workbook load — so paint, scrolling, selection, and navigation (which all key off the extent) follow the data automatically.

• Import grows to fit. After importing, the grid always includes the full imported range. A 500-row / 40-column file is fully visible and scrollable.
• Grow on the edge. Arrowing or Tabbing off the bottom/right edge adds a row or column, Sheets-style, so you can always reach — and type into — the next cell.
• Per sheet. Each sheet sizes to its own content; switching sheets recomputes the extent.

Growth is bounded: imports are already capped by the import guardrail, so there is no unbounded dense span to size against.

Try it

Import a CSV with a few hundred rows, or a wide one, and scroll down/right — every imported cell is there. Or select the last row and press the down arrow: the grid extends so the cursor keeps moving.

Verified behavior

Matches Google Sheets: In Google Sheets the grid is not a fixed rectangle: it grows to fit your data. Importing or pasting a range that extends past the current last row/column enlarges the sheet so every imported cell is visible and scrollable — nothing is silently hidden below or to the right. Pressing the arrow keys or Tab at the bottom/right edge adds more rows/columns (Sheets appends rows as you reach the bottom), so you can always navigate to, and type into, a cell beyond the current edge. Each sheet in a multi-sheet workbook sizes to its OWN content.

Imported data below the default extent is visible and reachable

Given

When I import x,y,z, then select A150

Then

• A150 shows x
• B150 shows y
• C150 shows z
• the active cell is A150

Arrowing past the last default row grows the grid

Given

When I select A100, then press ArrowDown

Then

• the active cell is A101