A problem with 100% width is that on a wide monitor actual statistics would be really far away from tag/suite names. Making it a bit wider than nowadays could be considered, but bigger changes are better done as part of a larger log/report rewrite that’s planned for somewhat near future.
The real problem here seems to be that tag names aren’t wrapped. That ought to be pretty easy to fix by forcing that behavior using CSS. Could you submit an issue about that?