PVE is based on Debian GNU/Linux - meaning you can install almost all things that are available in the debian repositories (exception being some packages conflicting with PVE (e.g. qemu from plain debian)).
This usually works well (e.g. our workstations here are running on PVE, and have a desktop environment, browser, devtools, and many other things installed) - however keep in mind that there is the chance that having a different piece of software on a PVE might result in problems, which few other people are experiencing
I hope this helps!