Is there a way to create/reflect 1-to-many relationships in the setup wizard?

Just stumbled across Mockaroo on my hunt for dummy data to create some CRM setup walkthroughs.
One thing I can’t seem to work out from the interface is if and how I could setup 1-to-many relationships in the setup wizard?

Here is what I am after:

  • 500 “contact” records with the usual email, name, phone, address, company, etc.
  • of those, 100 should be unique
  • the remaining 400 should be 40 companies with 10 associated contacts each

Is that even possible?
Cheers
Frank