It is highly recommend that you create the text content for your page in a word document before copying and pasting it into the editor. The main reason for this is that the Content Management System will log you out of the admin side of the site after a certain amount of time if the page is not saved.
This is done as a security measure to reduce the possibility of an unauthorised user gaining access to the site and changing the content. Also if the browser crashes at any point or the internet goes down, the page you are creating doesn’t save and is lost.
Creating it in a word document also means that you have a backup copy of the text for that page in case it gets deleted once it has been created and added to site, meaning that you don’t have to sit and retype the entire page of content out again.