I just noticed this today - I suppose it is a new feature?
When I pass my mouse over the tabs at the top a popup box appears.
Usefull indeed (eyes roll).
I have an older computer and it is (was) taxed to the maximum it could endure. Twice now, by passing my cursor over the tab names, the popup box tried to load and then froze the browser. I had to close all tabs and restart.
Considering that this new popup is useless and it causing issues, please allow for it to be turned off.