@Keet
If you have over a 100 tabs open you should review your way of browsing. It's not a problem for the computer but a mere human can not keep track of 100+ tabs.
I have multiple workspaces, each being for a separate general purpose (mail, Bash, SOL, etc etc), and have a dozen Firefox windows open across these with about 150 tabs total, most of which are bookmarked, and again themed within the workspaces. However, bookmarks will not retain the position on the page (how far you've read in a story, or which answer on stackexchange you find the most useful) - and, I don't reboot often (currently uptime is 22 days, I've had over 90 days up) nor generally close Firefox - it crashes often enough by itself - but when it restores the tabs, it will often bring me back to the same place on the page. My bookmarks are in a hierarchical tree, but the total number dwarfs the number of tabs; an export of them a year ago (transferring to another machine) is nearly 70MB, because I hadn't found a way to selectively export. And, I use a different browser for pron, so Firefox bookmarks and tabs are not affected by that. I'm definately pushing the capabilities of Firefox, as sometimes I've gone looking for a tab I know I opened only to fail to find it, or have tabs restored after a crash that I know I had previously closed.