Is there a list of them?

I can't remember any of the items that do, right now. :|

Thank you. (:

Theres the Magical Keepsake Box (increases 1-3 spaces.)

And there's the Multi-compartment Keepsake Box in the Cash Shop. It increases 10-15 spaces.

Oh, also you can zap your pets with the Pet Zappers and it may increase your pets' treasure spaces! Also there are random events. :D