If you read my posts regularly, you know that I love old things. I find such joy in giving life to lovely/sweet/beautiful/useful things from our past.
Children's pottery is a wonderful example. When my boys were babies, I had a collection of vintage (and a few vintage-syle repro) plates, bowls and two handled mugs that they ate from regularly. I even had them eat with those little sterling silver spoons and forks.
Yes, I suppose you do take a chance in putting something breakable on the tray of a high chair, but I just saw it as a teachable moment. What better way to gently teach them not to throw? And what did mommies and daddies do before plastic? They taught their children not to throw. Besides, the vintage ironstone bowls pictured above are extremely durable - I bet they've been thrown quite a bit in their day - and are perfect for learning to eat. The heavy bottoms keep the bowls from sliding across the tray.
I know, I know... clean up is a little more trouble with something you don't throw in the dishwasher, but if you aren't feeding multiples, try to take the time. It's not as if an oatmeal bowl will need a lot of heavy scrubbing with steel wool. Handwashing with soap will only be a few seconds more than prewashing for the dishwasher.