Do something efficiently and energetically. For example, She really went to town, not only developing and printing the film but making both mat and frame. [Early 1900s]
Act without restraint, overindulge, as in He went to town on the hors d'oeuvres, finishing nearly all of them. [Early 1900s]
Be successful, as in After months of hard work, their business is really going to town. [Mid-1900s]