Open a multi-page document. On the View tab, in the zoom group, click on Multiple Pages.
Use the Zoom bar (bottom right) to zoom in or out to see as many or as few pages as you like.
To return to seeing only one page click on One Page, which is in the same group on the View tab.
Your document will be quite small, so click on Page Width to make it fit the width of your screen.
Should be much bigger and easy to read.