It has been this way (dining rooms on 20 amp circuits) for decades. It is clear that the code making panels so far have all felt dining rooms need 20 amp circuits for receptacle outlets. Why? I never could find a valid rationalization. When I was an apprentice (30+ years past) I was told that this was because many homes had electric steam tables in the dining rooms that took a lot of current. Every steam table I have seen in home dining rooms was heated by oil lamps, candles or Sterno.
