Hello everyone!

I was curious about how I can go about autopopulating another table when a single select drop down item is selected. 

For example, I own a roofing company. My tables go from CLIENT to PROPOSALS to JOBS. Client is initial meeting (phone, e-mail, in-person etc.). Proposals are to create then send to said Client. And Jobs is after a job is won.

What I would like to do is in my OPPORTUNITY column, when I choose CONTRACT SIGNED in the drop down menu, I would like it to autopopulate my JOBS table. 

Any help is appreciated!