Risk Assessment

I assume you are using our ISO 27001 documentation toolkit. 

In that context, we do not recommend you merge those templates because of the following reason:

In the Risk Assessment Table you need to identify all the risks, no matter whether they will be treated or not
In the Risk Treatment Table you will list only the unacceptable risks, it would be an overkill to list all identified risks
Risk Treatment Plan has a very different purpose from the Risk Treatment Table, see the explanation here: https://advisera.com/27001academy/iso-27001-risk-assessment-treatment-management/#treatment

Together with your toolkit you got the access to video tutorials that explain you how to fill out each of these documents. 

These materials will also help you regarding risk assessment and treatment:
- Book Secure & Simple: A Small-Business Guide to Implementing ISO 27001 On Your
Own https://advisera.com/books/secure-and-simple-a-small-business-guide-to-implementing-iso-27001-on-your-own/
- Free online training ISO 27001 Foundations Course
https://advisera.com/training/iso-27001-foundations-course/

I like to purchase the (1) risk assessment table template and (2) risk treatment table template. I need the risk assessment output (unacceptable risk part) to use as input for the risk treatment.

My question, if I buy products (1) and (2) separately, can I integrate the two products so that the output of product (1) easily flow/migrate into product (2) as input?

All the products you mention are templates in MS Excel - therefore, you can adapt them (or merge them) as you see fit, and you can copy and paste the data from one document to another. 

On the landing page of each of those documents you can see a free preview and download a free demo of each document:

• Risk Assessment Table: https://advisera.com/27001academy/documentation/risk-assessment-table/ 
• Risk Treatment Table: https://advisera.com/27001academy/documentation/risk-treatment-table/