Highlight a column in the data and open the Go To window.
You can also use the Ctrl + G keyboard shortcut to access the Go To window. Now only the blank cells in the column you highlighted will be selected.
Delete these rows.
A similar trick will work for blank columns, just select Entire Column instead of Entire Row. Voila! You just saved yourself a tonne of tedious work. Go take a 15 minute break and relax, you’ve earned it.