by Don » Tue Dec 13, 2011 10:06 am
Hi and welcome to the forum!
This is where all of your macros can be stored. It is your "Personal Macro Workbook." This is created when you record a macro and in the "Record macro in:" drop-down select "Personal Macro Workbook." The benefit of having this is that you can save macros to this file and then use that macro on any Excel file that you have open. This is basically just common storage space for macros.
However, when you have this, it does open what seems to be a blank Excel window under the current Excel window. Don't mind it, you will just have to close it like you would a normal workbook when you go to close all of your other workbooks in Excel.