I have tried to set it with a js query but it doesnt seem to work.
Welcome to the forum!
I don't believe it can be done programmatically at this time
ok Thanks, its interessting because its mentioned here:
It looks like that property is actually for a table configuration setting that is available yet. When it the feature ships, autoColumnWidth will be controlled by a checkbox under Appearance->Advanced
Hi all, if you're interested in changing this setting before it's available in the editor UI, you can read my post about it here - Table column width feature request - #4 by mitchmess
Thank you! It looks like we just shipped an auto width checkbox under Appearance -> Advanced: