How to: Remove Tables from Queries (Visual Database Tools)
You can remove a table — or any table-valued object — from the query.
Removing a table or table-valued object does not delete anything from the database; it only removes it from the current query. For details about removing a table from a database, see How to: Delete Tables from a Database (Visual Database Tools).
To remove a table or table-structured object
In the Diagram Pane, select the table, view, user-defined function, synonym, or query, and then press DELETE, or right-click the object and then choose Remove in the resulting dialog box. You can select and remove multiple objects at one time.
Remove all references to the object in the SQL Pane.
When you remove a table or table-valued object, the Query and View Designer automatically removes joins that involve that table or table-valued object and removes references to the object's columns in the SQL Pane and Criteria Pane. However, if the query contains complex expressions involving the object, the object is not automatically removed until all references to it are removed.