Salem's restaurant scene has improved enormously over the past twenty years, partly because a year-round population of Bostonians commuting by rail (Salem is 25 minutes from North Station) has raised expectations. The concentration around Pickering Wharf and along Derby and Essex streets is the obvious hunting ground, but some of the better places are a short walk from the tourist core.
Turner's Seafood on Turner Street does serious New England seafood — clam chowder, fried clams, fish plates — in a no-nonsense room that gets very busy on weekends. Ledger Restaurant on Washington Street is a good option for something more ambitious, with a menu that changes seasonally. Ledger's Bar next door has one of the better craft cocktail lists in the area. For a casual lunch on the waterfront, the Pickering Wharf complex has several options, including raw bars and fried seafood that work well in summer.
In October, expect long waits everywhere. Reservations are essential; without them, plan for a late dinner or a long walk to find anywhere with seats.