As it seems the post asking for a default column width has been archived, I’ll make another post asking for the same.
Basically, it’s not clear to me why features have been provided for rows when creating tabular data but not for columns. There is no way to set default column widths (and also no way to easily measure the width of a column) so that means the only option to create uniform columns lies in physically measuring the width of a column on your screen using a ruler or something.
Additionally, there definitely seems to be a bug when selecting column widths, where if you go too small the column width automatically jumps to the largest size which is often somewhere past the width of your screen. Reducing this column width back to a smaller size, while appearing in the analysis, does not translate to the published dashboard. Leaving and reopening your analysis reveals the very large default width you just shrunk moments ago. The only way to solve this problem is to rewind your analysis step by step to the moment before the column jumped to the larger width, and then publishing that version of your analysis to a dashboard.
This is broken, and also very annoying, so if nothing else a fix for the latter would be appreciated.