Casual wedding party dinner for foodies in/around Campbell San Jose CA.
Aldo's in Los Gatos might be able to accomodate you here. Pretty good italian fare. Very friendly staff.
Los Gatos Brewery is another good option. The beer is better than the food, but the food isn't bad.
Both of these can handle a large group like yours.
Los Gatos Brewing Co
130 N. Santa Cruz Avenue, Los Gatos, CA 95030
Aldo's Ristorante & Bar
14109 Winchester Blvd, Los Gatos, CA 95032
If you want to stay in Campbell - you might try Olio on Campbell Ave. It is a bit small, but really good food, good wine list and pretty affordable. In Los Gatos, Tapestry is great and has a nice patio with a stone fireplace if you want to take the party outdoors - they do a lot of functions out there, in fact. They are also pretty good on price. I agree with lgphil that Los Gatos Brewing Co would be okay, but they have been really hit or miss in recent years - fun, festive atmosphere, though. If you want to go a bit high end in Los Gatos, Dio Deko is very good in the Hotel Los Gatos.