Hi there @Arthur Sekhyan,
Good question. You can display and show more products to users in a variety of ways within an email template. Displaying products within an email is all controlled by the Product Block added to the template.
This product block can be expanded to show as many products as you need either by manually selecting your desired products or having them automatically populated from your product feed/catalog. Along these lines of automatically populating products, you can certainly customize Klaviyo's product recommendation engine as mentioned in our How to Use Product Feeds and Recommendations article. As a note, codes for different event variables needed can be found in your preview settings in the editor (pictured below) Also our guide will help with common event variables.
Hope this helped,
Alex