Freedombase knows whether you want to create a new table, or to attach to an existing table, based on the entry in the (Class) Alias For field in the Freedombase Designer. If you leave the Alias For field blank, Freedombase will create a new table. If you enter an existing table name in the Alias For field, Freedombase will know that this System and Class combination is an alias for that existing table, and will connect to that existing table instead of creating a new table.