Facebook has a pattern of loading new content into the same tab endlessly, which Firefox tries to retain in memory. Probably it shouldn't, but I don't think there is a way to unload content you already viewed until you either close the tab or navigate it to a different page. Hopefully someone else has a suggestion.

But what uses 10 GB of RAM? Facebook uses 17 GB RAM, which group or profile uses 10 GB RAM? Even if I close Facebook, the usage is still 100%, it doesn't release memory! Memory is not released, it accumulates garbage in memory! Memory leak is endless. I can have 100 GB of RAM and it will always grow to 100%. Endless garbage collection in memory. Will there be an eternal memory leak?

When i play, for example, any video on Facebook, sometimes an error occurred on Facebbok, and the memory increased to 100% RAM and 100% cpu and the information that the virtual memory 100 GB (pagefile.sys) was exhausted.