Don't need anywhere near that much. On this 2012 PC with 32GB of RAM I have 3300 tabs open in Chrome and 3100 in Firefox. Plenty of RAM left over for other things too. I use The Marvellous Suspender for Chrome and Auto Tab Discard for Firefox to keep the memory and CPU use down. Session Buddy for Chrome makes it easy to manage them. I don't have anything as good for Firefox though (I'm using Session Boss, but would like something better).

When ff is set to restore tabs on launch, it does not load them until you click on them. There are also extensions that allow you to unload tabs without closing them. I've never been a fan of bookmarks for whatever reason and tend to have many of the same tabs open for months at a time.