To Add a Row or Column:
Click on the Table icon while you are in edit mode. A drop down menu will display.
To add a row, select "Add Row Above" or "Add Row Below". A new row will be inserted before or after where your cursor is placed in the table.
To add a column, select "Add Column Left" or "Add Column Right". A new column will be inserted before or after where your cursor is placed in the table.
To Delete a Row or Column:
To delete parts of the table, highlight the rows or columns you would like to delete and click on the Table icon.
Click "Delete Rows" or "Delete Columns" from the drop down menu.