Margins are the unprinted areas along the sides, top, and bottom of a printed page. All printed pages in MS Excel have the same margins. You can’t specify different margins for different pages.
You can set margins by various ways as explained below.
Choose Page Layout » Page Setup » Margins drop-down list, you can select Normal, Wide, Narrow, or the custom Setting.
These options are also available when you choose File » Print.
If none of these settings does the job, choose Custom Margins to display the Margins tab of the Page Setup dialog box, as shown below.
By default, Excel aligns the printed page at the top and left margins. If you want the output to be centered vertically or horizontally, select the appropriate check box in the Center on Page section of the Margins tab as shown in the above screenshot.