Excel version? And where would those files live in? Cloud, local drive or network drive?

Also, would users edit data in Workbook 2 Sheet B? Or is it for reporting source only?

If no editing of the data is required on Workbook 2. I'd recommend using either MS Query or PowerQuery to bring in data from Workbook 1.

Then it's only matter of refreshing data whenever workbook 2 is opened.