I am using Firefox as my default browser in Windows 10 Enterprise. Since making it my default, the computer takes forever to start up and often gives me "not responding" messages when trying to open a documents search or other tasks. When I open the Task Manager to stop a stalled task, I noticed that Firefox is using over 3800 mb of memory, more than three times as much as any other browser, resulting in over 70% of my memory being taken up. I am assuming that Firefox is therefore not sleeping or suspending unused tabs. Is this so? If so, is there an add-on or tab manager that will suspend currently unused tabs? I've tried to use the suggested tab managers but found them impossible to figure out. Why don't these add-ons provide instructions on how to set them up?

Thanks for any help or advice you can offer.