Baubles is a small addon mod and api that is intended to be used by other mods to add additional inventory slots to a character.
It adds 4 new slots: an amulet, belt and two rings slots. The baubles inventory is accessed by pressing the 'b' hotkey. It is probably a good idea to remap your normal inventory hotkey to the baubles inventory if you are going to be accessing it a lot.
This mod adds very little content itself - it is intended to be an addon for other mods.