i have heard that you can put an empty treassure chest in your inventry and then put excess items in the chest.
The only way I could get this to work is by dropping the chest every time I wanted to use it. I couldn't get it to open while it was in my inventory. It was just too much hassle to have to drop it, put what I wanted into it, then pick it back up again. It was simpler for me to just dump everything into the barrels in the battlefields, whenever I happened to be there.
