There's no reason, from a code standpoint, not to just have a separate, 20-amp, AFCI-protected circuit serve the dining room.
Sure, you might set a crock pot on a table ... that's the reason dining rooms are considered as part of the kitchen area ... but I don't see that table as meeting the 'countertop' that would require GFCI protection as well.
There's certainly no requirement that this circuit have anything to do with the kitchen or the kitchen counter. Code simply says you'll have at least two circuits serving the entire area - and that these circuits cannot serve other areas as well.
In this case, the AFCI requirement is certainly a 'curve ball' tossed our way!
