STEPS TO REPRODUCE
1. press ctrl + or ctrl - on some website with particularly small (or large) text to get it to the size you want
2. click click click around that site on the tab to read other pages and you get to use the zoom option you have, which is nice.
3. right-click a link to some page on that site and open it in a new tab (or use the middle button) and now you get the default zoom setting in the new tab.

EXPECTED RESULT
Other browsers will give you the zoom/size you have in the tab you're in when you open a link in a new tab. This makes sense, if you have a readable size in the tab then you'll probably want that size in the new tab you open too.

This, quite frankly, is a problem which - to me - makes Falkon unusable and a non-choice. It makes using tabs problematic to the point where it might as well not have tabs.