Your Werke table has only two fields? Then you could use it as a mapping table and use applymap to add Standort to the four Derivat tables. You will no longer need the Werke table anymore. You can also transform you NAELs table with the crosstable function or a bunch of concatenates to another form so you create a record for each Derivat instead of keeping all four of them in one record. This makes the next step possible. Next concatenate all your Derivat tables into one Derivaten table. The result will look like this:
You'll only have two tables left, but still all the information.
The Source field in Derivaten is used to store from which source table the Derivat record came.