really tricky brief I think, as what woiuld suit one familyt would not suit another, that is why there are so many sizes and designs to choose from in any one store - just look at Ikea's website for example.
But, for our family (of 4) we eat at the kitchen table, homework gets doen there, as does art and craft projects, I do my paperwork there, and we ofetn have another family round so it has to seat 9 people quite frequently. Kids cook quite a lot, and usually use the kitchen table as their preparation surface instead of ther kitchen worktop as it is more their height.
OUr kitchen is not huge, and the table is in the middle of it, if the table is extended to seat 9 it is difficult to open the dishwasher, freezer, or frankly to walk round the table if anyone is sat at it. therfore fro us the table has to be able to extend.
Wipeable, heatproof surface would be good, so I don't have to worry about mats for dishes straight out if the oven.
Drawers in it - not too bothered, I have a cutlery drawer in the kitchen anyway.
But, we are trying to move, hopefully to somewhere with a separate dining room, so what I would want out of a kitchen table in my next house would be different again.
hth