Sabrina,
That's my thinking! I tried putting ds at the table in a booster seat from about 13 mo. (with straps so he couldn't fall out, get out, etc.) becuause of space restraints and hated the mess he was constantly making on the table. When we finally moved in our house (and therefore had more room) I bought him a highchair. He seems to like it and I appreciate just wiping up the tray and not having him reach for things on the table. My friend's children didn't move out of their highchairs until almost three years old because it was just easier to contain them and their mess that way. They then moved into booster seats with straps for another year. But, her dining set is not easy for kids to sit in the chairs and comfortably eat. I plan on keeping ds in his highchair until he uses a spoon more efficiently, no longer feels a need to squish everything before he puts it in his mouth, and keeps bowls and plates right side up.