Help:使用視覺化編輯器增修表格/4
要增加新的欄或列，您需要指定想要插入的位置。一旦指定好儲存格後，a triangle will appear at the top of the column, and the left of the row.
Clicking on the top triangle allows you to add a new column before or after the selected one (or delete it). Similarly, clicking the left triangle allows you to add or remove rows.