You need 24" on every side of the table for chair sit and scoot space. If you don't plan on having any other furniture in the space, theoretically you could use a 60 x 72 table. However, if you plan for a buffet, sideboard or china, you need to subtract their depth from the floor area and then calculate how large a table based on the remaining floor space for it and the function of the chairs. I also like to consider space for someone to get up and move out of the room while other diners are seated. If you plan for a rug underneath, it should be 4' wider and longer than the table top without running into walls or furniture on the walls. If you need to seat more people, get an extension table, and make sure the leaves have an apron on them to match the table and are not just "planks" without matching trim underneath to unify the table's look when fully extended. Did I confuse you?
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Small dining room furniture guidelines
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