DareDevil has suggested reducing the number of PK3s that we have. Unfortunately, ET loads all of them at run-time, so we can't really tell when each was last used to play a map. You could manually delete or move the files that you don't remember playing recently and the server will cause a download if you are wrong. I should go look at mine to perform that cleaning-out.
I have 197 pk3s, taking up 2.02 GB of disk-space. Those are compressed files, so I might assume that ET de-compresses them as needed, but I don't now for sure. It could de-compress them into a "current-ma