We always recommend using a dresser as a changing table and that worked well for us, but if that doesn't work for you, this metal shelving seems like a good option for small spaces.
First, the shelving has a smaller footprint than most changing tables. You can actually order it to your exact dimensions here, which is what the author of this post on Living in the Family Room did.
The open shelves also make use of all of your available space. The best part is when you're done with using it as a changing table, it can easily convert into shelving in a closet, pantry, or bathroom.
Living in the Family Room.)