1(A set of) toy items forming a game in which children pretend to run a shop.
2US An amateur theatre company. Chiefly in the names of university and community theatre companies.
3A workshop presented in an approachable or enjoyable way, as one which introduces an activity to children, or which develops skills in a leisure activity.
Late 19th century (in an earlier sense). From play + shop [adjective, interjection].