When the whole table is selected, and that's what you must do if you want the changes to be applied across all cells, when the context menu is invoked it should contain the AutoFit Item, which has three choices when activated: AutoFit to Contents, AutoFit to Window, and Fixed Width.
Once the context menu is up, hitting A followed by F should do a Fit to Contents for every cell in the table. Were you to want Window, the character after A would be W, and fixed width it would be X.
Brian - Windows 10 Pro, 64-Bit, Version 20H2, Build 19042
One does not discover new lands without consenting to lose sight of the shore for a very long time.
~ André Gide