How can we separate the products on different pages?

You can do that only if you create products with basic fields (radio buttons, checkboxes) and then pass the total calculation to PayPal: https://www.jotform.com/help/275-How-to-Pass-a-Calculation-to-a-Payment-Field

1) So you can insert the products blocks:

2) Then you can insert the page break between those blocks:

When you do that you can pass the calculated price to the payment field by using the above guide.

Could that work for you?

Please advise.

Thank you!