My ds is 3.5 and goes to pre school 2 days a week, he does 'soc a tots' at ore school. We do an M&T group on a Friday and I take him on regular trips out and swimming, but he doesn't do any organised lessons as such.
My SIL takes her dd (same age) to swimming lessons, ballet, tennis and French lessons on top of pre school.
She thinks my ds needs more, I think she does too much. Got me thinking about what others do.