Not only can you add rows and columns to any of a Word 2016 table's four sides, you can squeeze new rows and columns inside a table. The secret is to click the Table Tools Layout tab. In the Rows & Columns group, use the Insert buttons to add new rows and columns.
To remove a row or column, click to position the mouse, and then click the Table Tools Layout tab. In the Rows & Columns group, choose the proper command from the Delete button menu.
Rows and columns are added relative to the insertion pointer's position: First click to select a cell, and then choose the proper Insert command to add a row or column relative to that cell.
Select a row or column before choosing a Delete command to ensure that the proper row or column is removed.
When you choose the Delete→Delete Cells command, you see a dialog box asking what to do with the other cells in the row or column: Move them up or to the left.
A mousey way to add a new row is to position the mouse pointer outside the table's left edge. A + (plus) button appears, as shown here. Click that button to insert a new row.
Likewise, if you position the mouse pointer at the table's top edge, click the + (plus) button shown here to insert a new column.