Firefox has become very slow to load tabs

Firefox ver 152.01 64 bit on win 11 recently very slow to load tabs, and if on you tube very slow to show pictures of the video's, also in Task manager with two tabs open shows 1,154 MB and in the App's section show 14 Firefox open. If I use Edge they open very fast, and & have now stopped using Firefox for this reason. I have been using Firefox for many years without any problems but now not really usable any more, unless this can be fixed. John