Normally you cannot enter new lines end of pages but you can do that by using {{subst:}}

Example:

page 1 (blank):

page 2:

(a lot of new lines)

<noinclude></noinclude>

So when you subst page 2 to page 1 it'll be full of new lines and nothing else. And when you for example look diff it says no changes made.

Example on fiwiki, look for Fiwiki-tools-bot's edits when it cleans the sandbox.