I have 2 tables:
A rental table, which has the fields [CustomerID], [BookingNo] (primary key) [ProductID], [DateOut], [Paid], [Owes] and [ReturnDate].

A product information table, I have the [type], the [cost] of product and [Description] (memo) as fields.

For the rentals table, the [Owes] field is calculated from [cost] (from the product info table) minus [Paid]. However, these fields are in separate tables. Can I still perform the operation to find out [Owes] when the required fields in the calculation [cost] and [Paid] are in separate tables?
I know you can't insert calculations in tables, but even if it is used on the form, the calculation is still spreaded accross 2 separate tables.

I do not see any field in both tables that would allow you to join them in a query.

You should use a query to calculate balances/money owed and not a table