You can re-order the steps by selecting (multiple) rows in and dragging them - using the left column - to the new position. 

You can insert or delete (multiple rows) by selecting them and clicking on the insert or delete icon in the right column:

Steps can easily be deleted clicking on the cross in the right column as well:

Test steps can contain HTML markup, e.g. if you enter "set the temperature control to <b>20</b> degrees", it will be shown as "set the temperature control to 20 degrees". When editing an existing item, you can also hit "Shift Enter" to open a rich text editor to modify the cell's content.