Is there a console command (or something) which can be used to reduce the amount of spawning monsters? Thanks.

No, I don't think so. But the spawning shouldn't be that bad usually. I think that only certain enemies respawn and if you learn where such enemies are and avoid their positions, you shouldn't run into too many of them next time you are in that location.

Why would you want to reduce the spawning rate!? Those re-spawned monsters are a gift, really! More XP and more gold for you ;)

OK, thanks. As for why I'd want to reduce the spawn rate, it is because when I want to get somewhere fairly quickly they are a mega pain in the butt slowing things down ;)