Our marina in Portsmouth - New England Boatworks, aka: East Passage Yachting center, has a restaurant called the Sail Loft. Great food and grog - although not a T-shirt, sandals kinda place. Boats can tie-up free while visiting the restaurant/bar. Simply call NEB (VHF Ch9) in advance for directions to available transient slips, or pull into the fuel dock and speak with the attendant.
Other options we've used with dockage include: The West Deck in Newport with transient dockage at West Wind Marina, Goat Island Marina Grille in Newport, and Wickford Village, which has several nice restaurants with free dockage at the Town Docks. There are many more other boaters here may recommend.
Steve