Too Clever By Half

This is your blog, on a diet.

Blogger automatically pagenates your blog pages based on size. Exceed 500 kb, and Blogger continues your blog onto an archive page.

This feature (or bug if you prefer) is not going away. You can't disable it, but you can manage it.

Write a post, and it will show up at the top of your blog page. Keep writing posts, and eventually your posts will spill over into archive pages, with links to older posts at the break.

Two things determine where that break is--and you only control one of them.

It's a ceiling, not a floor

Bloggers with administrative privileges can limit the number of posts per page at Settings > Posts > Max posts shown on main page

This setting lets you control the size of dynamic pages. 

Sort of.