are we talking about an HTML Table or a Database table?
For an Html table in HTML Editor 3, select the data in a cell, and you will see to the left side of the cell an up arrow, x and down arrow icon along the side, click the up or down arrow to add a new row. along the top, you will see a right arrow, and x, and a left arrow, clicking one of the arrows will add a new column.
see the attached screen shot.