bluecrabmd: It depends on the design of the table. Steve is right that 72" x 36" is the minimum for a rectangular, but even that may not seat eight in certain configurations without leaves (either in the middle of the table or that slide on the ends). You have to do the math. Measure the chair(s) at the widest point, then the measurement between the legs of the tables. Allow at least 2" wider than the chair for wiggle clearance. Typically allow 24" of linear table space, per guest on the table surface. Duane Collie

Banquettes rock! I think they're great for kids if you get removable mid or dark patterns covers that can be washed. I used to like hard chairs but found out that my kids sit much better on upholstery so I've given in to that. Not sure about the radiator issue but banquettes can provide great storage space if you use cabinets for seating (BESTA line probably has some good dimensions - their cabinets have finished tops). I helped my sister design the one below. She has made a lot of changes in her home, but this is the one that she says has made the greatest improvement because of how it has changed how they use the space. The whole family really loves to hang out there and the area feels warm and welcoming in a way that it didn't before.

The width needs to be about 6ft and the length needs to be 6 ft expandable to 8 (9?) ft. We want to seat 8 normally and seat up to 10. How big does it need to be to seat 8 and 10? Our dining room space is 15x11, but is open on two sides so it will fit in the 11 ft dimension This company based in the UK has exactly what I want but would like the easier route of ordering from a US company. I could possibly get one custom made if I cant easily source one. Does anyone know of a US company that makes tables like this? https://www.berrydesign.co.uk/dining-tables/square-dining-tables/ This is an example of one Here is the floor plan, it would go in the dining room (the columns have been removed)

Try Ballard Design; they have some cool looking tables in all sizes and shapes. As does Pottery Barn and Restoration Hardware.