Can you tell me if the Key field (in gold on the field list) for the Special handling table is the field
[Article ID]
If it is, then you can make a relationship where One Special Handing has many Incoming Requests, and let the system create a field for you called [Related Special Handling].
Rename that to be called [Article ID mirror] and change the field type to be formula (either text or numeric according to the field type of Article ID), and then set the formula just to be
[Article ID]
The lookup the Special Handing words from the special handling table down to the incoming requests. The reason for the mirror field is that when you enter an Incoming request, I'm guessing that not all items have an entry in the Special Items table, so I don't want to force you to choose an item # off the Special handling table for the Incoming requests that do not have an entry in that table.