When Excel starts a default new workbook displays. This workbook contains many of the default settings for Excel and it can be customized so it looks the way you want it to look.
You can configure the defaults for your starter Excel worksheet if you place your settings in one of the two Excel templates; Book.xlt and Sheet.xlt. Neither file is required but, if you have one or other, or both, stored in your XLStart folder then Excel opens them whenever it opens and uses the data you have stored in them as its own default settings.
When you’re creating either or both of the files make sure to put the relevant settings in the right file. Book.xlt should contain the defaults for all new workbooks such as styles and toolbars.
Use Sheet.xlt for options appropriate for all new sheets in a workbook which are added when you choose Insert, Worksheet. A word of warning, when you save a workbook as sheet.xlt make sure it contains only one Sheet.