hi Icemania,

From what i understand you want to change which table of the linqdatasource for updating a record in a gridview.

I would suggest you try to use Stored Procedure  for  LINQDataSource .

Using Stored Procedure with  LINQDataSource Control in ASP.Net

http://www.codedigest.com/Articles/ASPNET/293_Using_Stored_Procedure_with_LINQDatasource_Control_in_ASPNet.aspx

i hope it helps you.