What type of field it is?
If it is a single row field then you cannot store multiple value in it.
However, You can show all the values using some separate like "," so it will display like abc,aaa,aass. You can use aggregate function to achieve it.
If it is a multirow field then you have to find the unique identifier for each row and have to join the same in the query to get a value.
I think you could default the fields individually, but only for one record. So you build a personalization on manufacturer_name fetching the manufacturer_name based on the inventory_item_id, etc.
But you would not be able to populate a multi-record block that way, only the current record you are in.
But do you have more explanation on what you are trying to achieve, because it seems the data you already have in xxdpe_mfgpart_details you want to populate somewhere else? Either that somewhere else is a standard Oracle eBS entity, so why not interface it to there?
Or it's a custom form and why not build a view on your data and display that? Why do you need to populate it somewhere else?