To enlarge any web page, press Ctrl and + together (as many times as is required).
To reduce the size of a web page, press Ctrl and - together.
To revert to the default size, press Ctrl and 0 together.
If you have problems printing the grid larger, use the above tip to make it a decent size on your screen. Then press 'Print Screen'. (Absolutely nothing will seem to happen but you've actually captured a picture of your screen onto your computer's clipboard).
Open a new blank Word document, right click in it and select 'Paste'. (A picture of your screen will magically appear in the document). If the picture isn't the right size for your needs, click on it to bring up the 'handles' around it's edges. Click-and-drag on those handles to get the picture to fit. Then print your Word document.
Chris