How to free up the storage shown in the bottom right corner?

(This might be a stupid question, but unfortunately I do not know the proper name of the thing I’m worried about, so I can’t easily look it up)
I have been using Paraview 6.1.0 on Windows 10 and with everything I do the little storage bar in the bottom right corner fills a bit. It does not empty when I delete items from the Pipeline Browser or when I restart the application.
It is now at 85.9% and I fear it will soon fill up completely. How do I clear it?