The Medford Public Library invites everyone to a celebration of the new Charlotte & William Bloomberg library building, which opened in January. There will be craft activities, a scavenger hunt, photo booth, historical map display, and more. Mayor Breanna Lungo-Koehn will preside over a ribbon-cutting ceremony at 1 p.m. The day also will mark the grand opening of the Chapters Coffee Carts concession operation on the second floor.