Advantage of more than 1 tablespace on 1 disk?

Hi,

I've got a database with massive tables which fall into 2 categories:
Tables which don't change often but get read a LOT, and tables which
are heavily added to continuously and sometimes read.

Would there be any advantage in moving the latter logging tables to a
separate tablespace, bearing in mind it would still be on the same
disk?  Or have I kinda missed how tablespaces work?

Thanks

Thom