It's full-day kindergarten and the kids rest on mats on the floor. It comes after recess and lunch, so there's no need for socializing. They've just done that for an hour. A child, or two, might fall asleep, but most just rest, read, or color (which is allowed in some classes.) Choice time is something completely different. The children have access to the whole room, but can't just sit around and socialize.
Resting/reading/coloring on a mat is way more comfortable than putting your head down on a table.
Follow Mothering