Deci..
Am tras un table Server_list in design.
Am codul de a intreoga :
DataClassesDataContext dc = new DataClassesDataContext();
var interogare = from ceva in dc.Server_lists
         where ceva.Server == "a"
         select new { ceva.Server };

Totul merge bine...
Si cod de a adauga:
DataClassesDataContext dc = new DataClassesDataContext();
Server_list server = new Server_list { Server = "adsda", Comment = "asdasd" };
dc.Server_lists.InsertOnSubmit(server);
dc.SubmitChanges();