Looking for quiet dinner spot near Bethesda or F.Hts Metro for 8 old friends to catch up
Decent, reasonable food yes, but just as important space and noise level to enjoy a reunion of 6-8 baby boomers.
Persimmon, which is at the far southern end of Bethesda (going towards Friendship Heights) is wonderful and would probably be quiet enough as it isn't very large. In nice weather, you could walk it from either Bethesda or Friendship Heights. Also try Newton's Table. The restaurants in Friendships Heights are by and large not very good though of course there is Range. I haven't been, but I am guessing from the size of the place and the popularity that it is not quiet and that you can't camp at the table.
Indique Heights would fit your bill. On top of the FH metro station, beautiful and quiet interior, excellent Indian food.