Long press on the row number of a row which you wish to start at. An indicator will display to show that row has been selected.

Also a line will display at the top and bottom of that row on all columns with 2 little handles (boxes). Drag either the boxes to extend the rows,up or down.

With the appropriate rows selected, a popup menu should appear. Select the function on the menu. NOTE: Ther maybe a menu item for More that if selected will show additional menu items. NOTE2: depending if you're in read or edit mode a different menu items will appear.

At the top left of the WPS office part of the screen with be either the word Done or Edit. Touching either if those words will switch modes, with text briefly appearing to indicate which mode has been changed to.