Select the data range (or the entire worksheet)
Go to the Home tab
Click Find & Select
Click Go To Special
Select Blanks
Click OK
Right-click any selected blank cell
Click Delete…
Choose Delete cells up, or Delete entire row, depending on your layout
Click OK
If needed, repeat for remaining blanks
Alternative: Select the data range
Go to the Data tab
Click Filter
Click the filter drop-down on a key column (e.g., the first column)
Clear (Select All) and then select only non-blank values
Select the visible rows
Right-click and choose Delete Row(s)
Clear the filter after deleting