The file size increases and loading / saving time also increases. Before we go into WHY it creates it, just understand the impact. In either case, Pivot Table automatically creates a copy of the ENTIRE DATA. When you create a Pivot Table, there is raw data either in the same workbook or it is connected to some external source. Read more to understand when to use and when NOT to use this feature. That solves the file size inflation problem. Right click inside pivot, Pivot Table options, Data tab, clear the checkbox Save source data with file. You can ask Excel NOT to save the copy of the data and save on file size. This increases the file size and also slows down the open / close operations. Pivot Table creates a copy of the source data and saves it in the file. It relates to files containing one or more Pivot Tables.

Although there are many reasons for large Excel files, one of the reasons is easier to manage and it is largely unknown. During the discussion, one of the problems we discussed was large Excel files. Today I was conducting an efficiency optimization session for Risk Management team of a global bank.