Update existing records with new relationship table

I have done this before via a table to table relationship and not just a report link.  What are you using as your key field in the Jobs table?  If it is something that is (or can be included) in the Projections table, you can create the relationship.  If you're wanting to add in the fields from the projections table, create that table as the parent and the jobs as the child, then add those fields as lookup fields.