@tipping
This is a missing feature on tablets, I would call it a bug.
There was a feature request about but it is old and got only one vote.
https://forum.vivaldi.net/topic/40804/remove-tab-bar-in-tablet-version?_=1634811546727
You can report it to the bug tracker, search for bug in the help page > F1 to get information how.

Cheers, mib

Thank you for your request. As this post has had less than 5 votes over 4 years it will now be archived.