My family will be taking my New York City born-and-bred mother for a 75th birthday weekend in Williamstown mid-June. I'm wondering if anyone might recommend a good place for earlyish dinner on the Saturday night -- it would be a party of 9, including a couple in their 70s and a couple of reasonably well-behaved kids ages 9 and 6. We're looking for someplace celebratory but not overly formal, with good, fresh food and a comfortable atmosphere, ideally not too loud. And one of us is a vegetarian. Price is no object, but as I said, we're not looking for anything very formal. Any ideas?