An oval shape offers more flexibility because you can sit people at rounded edges in a pinch.

Round twbles typically have too much wasted width in a smaller room. i had a round pedestal table years ago with a leaf that worked well for my needs since it couodcbe exoajded for dinner parties. But with the oeaf it was essentially an oval table 🤷‍♀️

It’s the position of the table legs that limit seating. You can’t put a chair in a spot where the person’s legs will bump into the table legs.