Firefox eating up RAM

I don’t find a better group to post my question. I think it might have to do with security.

Anyway, here is my problem. Some Firefox page slowly eats up a lot of memory on my Windows 10 PC. Sometimes some page can eat up 10GB RAM. The fans on my PC starts to make lots of noise and my mouse starts to slow down. I have to end the process from Task Manager to release the memory. Then my PC responded smoothly again. Why? What’s the cause and how to fix?

Firefox experts, no answer?