Hey all, wanted to make sure folks interested in this feature request saw Matt's announcement post about new table features including Auto-column-width mode, Custom sort modes, and Multi-column sorting. Tess also noted this here.
"Auto-column-width mode" should solve many of the requests and use cases tracked above. 
I'll plan to close out this feature request, as we've launched the solution to "How can automatically fit width of table column?". Thank you all for surfacing the need for this feature!
These other requested features below, which came up in some of the above comments, are not yet solved for:
It would be great to specify the width of a column like:
- Fixed size (in pixels)
- A set percentage of the total width (%)
ideally we could have a field in the dynamic columns which specifies the columns widht
Then i could store the user preferencs in a DB and set the table to their last preference.
We're still tracking these requests for "User-defined, persistent table column widths" and specifying fixed column widths. Let's continue using this open Feature Request topic to track interest in those features. We'll keep noting +1s on that thread in our internal tickets for engineering, and we'll update that thread when there's movement toward implementing those features!