Multiple TinyMCE textfields for Pages

I’m looking for a way that when I make a page that I have multiple TinyMCE editors where I define in my template that I want to use where what TinyMCE content must be placed.

I could use Custom Fields, but it’s very hard to type here more content than a couple of lines.

I already use templates, so that is not the problem, the problem is to add multiple manageble content boxed in the admin interface I think.