Although the terminology at first can seem a little confusing, Excel 2013 uses the term workbook to refer to the Excel file, which might in fact comprise multiple worksheets. Each worksheet appears in its own tab. When you first open a new blank workbook in Excel, by default the program displays three blank worksheet tabs. You can add to those worksheets as needed by creating a new blank worksheet, and you can reorder the worksheets to appear just the way you want them to.
Open the workbook you want to use in Excel 2013.
Click the New Sheet button to the right of the rightmost worksheet tab.
You can rename a worksheet by right-clicking or double-tapping the tab at the ...