What is big? And why do you need big to filter, sort and pivot,...
Plenty of data generators can be found via a simple google search. Excel for one can create fake data as well. Download some data, then use some randarray() and index()/match() combo and fill entire worksheets with dummy data. Save a couple of files. You quickly end up with millions of rows of data. More data then an excel sheet can hold. But one can analyse with Power Query and Power Pivot.