Click the arrow next to the icon to open the Insert Cells toolbar, where you can insert cells, rows, and columns into the current sheet.
Tools bar icon:
You can select the following icons:
Moves the contents of the selected range downward when cells are inserted.
Moves the contents of the selected range to the right when cells are inserted.
Inserts an entire row. The position of the row is determined by the selection on the sheet.
Inserts an entire column. The number of columns to be inserted is determined by the selected number of columns.