Denise,
We are often at SB and will also be there at Easter.
I also know the Foresters Arms at Frogham and they do nice food there, but as you may want to walk rather than drive..... there is the Fighting Cocks at Godshill.It is a ten minute walk from the SB entrance or 5 mins walk via a short cut out of the back of the site. The food there is superb (or well munch as my daughter says. They do a really good range of food there and have a childrens menu as well.
I think the food is much better than the Woodside at SB, although that isnt bad.
We always wander up to the Fighting Cocks at least once while we are there.
They do reservations as well.
Just one thing, no streetlights in Godshill although there is a pavement, so if you go there in the evening take a torch.