We're interested in brunch on Sun., 10/15, around 10:30/11:00 for approximately 10 people. Do we need to make reservations for that?

I would make a reservation.

Yes. That way they will have your table waiting

It is best to make a reservation. My friend and I lunch there on a Friday once a month. Excellent choice.

They don't open until 11:00 so you probably don't need a reservation, but they would appreciate knowing that they will need to set up a party table.