Reducing query size - querying only data in one table that also appears on all other tables

Hello.

I have a 'Product' table, it has a 'Product Code' column and multiple attribute columns. It is an enormous data-set, as it has all the product a company as produced in its history.

In addition, I have an 'Inventory' table and a 'Sales' table. These also have a 'Product Code' column.

In order to reduce my query size, I want to query only the 'Product Codes' in the 'Product' table that appear in both the 'Inventory' and 'Sales' tables. 

How do I do this?

I've started with something like this, but it's not working, I may be way off:

= Table.SelectRows(#"Product", each List.Contains(Table.Column(#"Inventory", "Product Code"), [Product Code]) and List.Contains(Table.Column(#"Sales", "Product Code"), [Product Code]))

Alternatively, maybe I can do a sort of lookup column where if Product Code appears in 'Inventory' and 'Sales', mark an "X", and then query only rows that contain an "X"? But I haven't figured out the code for that route.

Thank you!