Hi! I suggest , you should start with a new workbook, then go to the Data Tab. Select importing with an excel power query or a power pivot. Import your issued workbook in this query. See the videos how to filter only the populated ( not empty) fields. Export your result to new table/workbook after filtering. Or try out making a database from it with MS Access for future tasks. Millions of rows are not performant content for excel. Go get it into a database, I recommend. Greets, Eva
Click Ctrl+End, you will be at the end of your former range. Select all rows from your data end till that place, After that on ribbon Home->Clear-Clear All (that icon is on the right site of the ribbon).
Save your file (or reopen with saving). Click Ctrl+End again to check if helped.