You cannot get info from another table into a formula directly. You have to create a Lookup field or a Rollup field, this is in case you have a Linked Record of course. Once you bring the info into the table, you can use it in your formula.
Then you can better change the setup. Add a formula to the Primary field, something like Newest Lease, Home Owner Name. Then in the other table link the Newest Lease to the Home Owner and rollup that field.