You can set the .widths property of a grid widget to a list of column widths in pixels. Any columns thus set to 0px wide will be completely hidden from view and skipped over when navigating by cell. Grids will also automatically hide any rightmost columns that don't fit within the width of the widget, so making leftward columns a bit wider can scrunch the secret columns out of view. (Columns have resize handles in between column labels while in Interact mode!)