To make the excel printer friendly, we could manipulate the size of the excel sheet to fit our requirements.
We could set the size of excel to A4 and A3 in a couple of simple steps.
To change the size of your excel sheet to A4 and A3 got to Size Under the Page Layout tab.
As you can see we could set the size of the excel sheet to match with our printing size and page requirement.
Hope this helped.