So far the only use for these is to use up some of those irritating empty storage slots.
The pack works like a normal one so you could use it if you can't part with it but the other garbage is just that,his jug=booze his bow=bow his horn=-1 storage space.
Perhaps it was another incomplete quest or perhaps just another sick joke like all of Gwen's junk scattered through the game meant merely to see how long they can get people to waste storage space on them.