Link table help without duplicating informaiton

I need to link a few tables together in order to receive information via lookup or rollup, but it seems I have to input duplicate information in order to accomplish this.

Example: I need to link Projects to RFQ. However, not all projects will require an RFQ so if I link the tables together by job number and an RFQ was not inputted it is a new record, but it adds this information to RFQ leaving an abundance of blank fields. How can I get around this without linking a table where I have to input duplicate job numbers?

Ideally, I’d like for any projects that have an RFQ to automatically be added to the projects page once the status has been changed to accepted with certain information auto-populated. (I think I can accomplish this with Zapier)

This is very hard to explain so feel free to ask questions or I don’t mind sending a read-only link for help in understanding.