It depends on what kind of games. I had about 20 games on my Quest 2 64Gb and still had plenty of space. The size of the games should be displayed in the store.

So I now have Asgard's Wrath 2 (30GB), Assassin's Creed Nexus (21GB), Red Matter 2 (9GB) and a few other small games and apps on it and now have about 30 GB of free memory. I think that's enough for now and if not, delete and reinstall if necessary, it's very quick.