Can I edit column widths in Notes on macOS Sonoma?

Maybe try this

Resize Table Columns

1. Tap to place the cursor in the column you want to resize.
2. Add spaces or text to extend the column width. The table automatically expands to fit.
3. On Macs, hold Option + Return to quickly add empty lines to increase column height.

Resize Table Rows

1. Tap to place the cursor in the row you wish to resize.
2. Press Return/Enter to add empty lines which makes the row taller.

It may take a few seconds for Apple Notes to figure out the new spaces, text, or lines before expanding the table size. You can repeat these steps to gradually change the columns and rows to your desired size.