Brief Summary
I can deactivate the option "Always show website titles in tabs" within the "Appearance" settings. However, the minimum size isn't well set at least how I would imagine how it should be.
Details:
This is with showing the titles:

This is without showing titles:

This is how Safari does it:

Honestly, I would prefer the tabs to become as small as what Safari presents when not always showing titles. I don't see much of a gain having such wide tabs without titles.