I just released 1.0.2 which fixes the date format to use ISO 8601 instead which is built to sort lexicographically.

Concerning the table issue, I tried my best to get the css working for the size, but I'm not sure what would be the best fix for this.

Contributions are welcome if someone would try to fix this:
https://github.com/GabLeRoux/webextensions-history-browser