Table Block: cannot see more than three columns at a time when adding new columns

[designsimply]

Steps to reproduce:

1. Add a table block.
2. Click the "Edit Table" > "Add Column After" option several times.
3. Note that you can only see 3 columns at a time and a horizontal scroll bar.
4. Switch to Edit as HTML then switch back to Edit Visually.

Note: instead of switching to Edit as HTML and back, you can also save and refresh the page or save, close, and re-open the post.

Result: when adding several columns to a table, you cannot see more than 3 columns at a time until the view is refreshed.

Video: 1m8s
^{Seen at http://alittletestblog.com/wp-admin/post.php?post=14085&action=edit running WordPress 4.9.7 and Gutenberg 3.4.0 using Firefox 61.0.1 on macOS 10.13.6.}

^{h/t @mermel for the original report (internal reference: p1532989996000185-slack-p2-gutenberg)}

[talldan]

I think this is no longer an issue since the table block was re-written. @designsimply - are you able to reproduce it?

[talldan]

I've set this to close once #9801 is merged. That provides more control over table width, and sets the default width to 100% for new table blocks.

[designsimply]

@talldan! My apologies for missing this @ mention earlier!

I re-tested just now and found that I was able to add 8 columns and no horizontal scrollbar appeared. LGTM! 🎉