See this reference site: http://alwaysjudging.com/archive/ It's loading new posts on scroll down, similar to Infinte Scroll plugin. (But I'm unable to get the Jetpack Infinite Scroll plugin to work on a static "archive" page using a query of posts, so I saw this instead.)
Ho would I implement this feature on a page?
When I view the source of the referne site above, it shows the script is loaded here: http://alwaysjudging.com/assets/js/scripts.min.js
It appears that the selector involves ".post-nav" and ol li tags.