You might think it is trivial, but if you try to delete rows by selecting them and hitting the "Delete" button on your keyboard, you will only erase their content, not the rows themselves.
Hitting the “Backspace” will not get you much further, even less, in this case you will only erase the content of the active cell.
Watch the video to see how you can get rid of whole rows.
Using this method, you will have the selected rows "vanish" completely, and the data below them will scroll upwards and take their place. This way your table won't be left with empty rows instead.
Select the rows carefully by dragging down from the center of a row header. Then, right click and select “Delete”.