The shortcut key to close the workbook is:

In Microsoft Excel, pressing Ctrl + W closes the active workbook window without closing the entire Excel application. This is a widely used shortcut, especially when managing multiple files at once. When you press Ctrl + W, Excel will prompt you to save any unsaved changes before closing the workbook.

For example, if you have multiple workbooks open, using Ctrl + W will close just the current file, leaving the rest open. This allows you to continue working in Excel without interruption.