Our new Brooklyn house is satisfyingly situated on the East River and on the seam between Brooklyn Heights and Dumbo, but it is super-compact. We needed an efficient dining table to accommodate 8 people in a tight space. Looked at round, which is convivial and begs for a lazy susan. But I think 4' square is the way to go. At two per side it's snug/intimate, and it works for only 4 as well. It is efficient to fabricate, too -- a 4'x8' sheet of plywood cut in half makes the top. Such a table must be pedestal-supported. With 8 diners around it, no room for legs.
The inspiration came on a ferry ride from Capri to Naples. As we pulled into the Naples harbor at Molo Beverello, along the left side was a long, slender, industrial pier with an enormous, round platform that I can only imagine is a helicopter pad. It was supported by an arrangement of diagonal concrete members that struck me as poetic and structurally elegant. I snapped a quick photo as we floated by, and this became the structure for the Naples table.