It doesn't really make a difference what the tabs are, could be a YouTube video cued up for later could be a simple text based forum, could be something I'm looking at on amazon, could be a blank new tab page. All of them will continuously eat up mor...
I've been having the exact same problem for over a year now. Even with just one inactive tab open in the background if you leave the browser running too long it will continuously allocate itself more and more system memory until it hits 99% and windo...