A 2 GB cache is not atypical (mine is 1.8 GB). If you clear it it will come back anyway. Maybe time to think about expanding storage. A 2 TB drive can be had for less than $100 now.
There are utilities like Cocktail that will clear them. I don't know if you can just move them to the trash and reboot, but that would probably work OK. I just don't worry about it.
Does a desktop Mac support hibernate? If so, you could save some space by disabling hibernate and deleting the sleepimage, which will be the same size as installed memory.
From a Terminal session:
sudo pmset -a hibernatemode 0
sudo rm /var/vm/sleepimage