Form Page

I have currently using Form Screen to add a rental job. Basically all details will park in this sheet (as below), Rent sheet. Usually, one client rent for one or two machines which we not really mind to fill in the form twice for same client, if rent for two machines.
What if we want to improvise so that user can add multiple items with same client and the most important thing still park at the same sheet (as below).

Appreciate if someone can give me an idea

If I understand your request correctly …
You have to relate two tables: in one you write all the data relating to the rented machine, in the other you write the user/client information data.
You need to create a relation column between the two tables that has the user’s code or email as a key.
But in your current table it seems to me that the “Client” column is merely descriptive. I’m wrong?
Let me know.