Timeline provides a unique feature of Infinite Load for posts. Posts that are selected from the query builder can be set to load automatically in the timeline on the scroll. This is very useful when you display posts dynamically on the page. All posts will load in a predefined timeline design. You do not need to manually set a number of posts to display on each page and design timeline again for it.
Read How Query Builder Works for Post Timeline?
The setting can be found under Content (tab) > General > Infinite Load. Set toggle to Yes. It displays all query posts with infinite load pagination.
Note: It will display the x number of posts for each load; where x is the value that entered in Post Per Page setting.