The Largo da Se Plaza is just a short walk from Largo do Senado, or Senado Square. It is small, but has plenty of places to sit. There isn't much to see other than a fountain and a cross, but if you are near Senado and would like to sit and relax in a place that is far less crowded, this is a good stop.
I like how it is tucked in next to a winding road, and also has a pedestrian only walkway that seems to drop down out of site behind the plaza. It also has more of the tile designs that you find through out Macau.
I don't know if Largo da Se Plaza is the official name, or if it even has a name, but that is the name of the street it is on.