It's definitely a small trunk, but I consider it a limited-use vehicle anyways and just use another car if I have something big to move along with multiple people. As of last weekend, though, I can confirm that a big pack of toilet paper from Sam's Club will fit in the trunk, under the package shelf and with the seats up, with room to spare for several other items.
Other than that, I've loaded mine up on different occasions with automotive tools, computers, bags, and all sorts of miscellany without issue (often folding down the back seats). Sometimes you have to get creative, but it's good enough for me.