Thanks for your suggestions!  I ended up sending an email and a general manager wrote back to me very quickly and answered my questions.  We had a good time at the faire and my son was happy that he could eat lunch there!
But those with nut allergies should know that there is a vendor that sells roasted nuts.  The booth was thankfully not near where we bought our lunch.  I also saw a Thai food vendor (I didn't check their menu but Thai food always makes me think of peanuts).

Call the kitchen.  508-866-8346.  Speak with Danielle.  I've already spoken to her.  She is lovely and we've come up with a few safe choices for DD.  She gave me her email address so I can keep in touch when I have a firm date that we will be there.  (I think she told me her child has some allergies....or that is someone else at a restaurant I was calling at the same time - LOL!)

This might help because their menu is labeled for some things:http://kingrichardsfaire.net/eat-and-drynk/

I haven't been since I was a teen, but it was fun. Hopefully you can find something there that works.

Hi,
Anyone from MA who has gone to this faire?  We are going next weekend and I was wondering if there is anything my son can safely eat there for lunch (he's allergic to nuts and shellfish).

Thanks,
Irene