Click "Insert Table Columns to the Left." The columns to the right will shift. If you selected a cell in the last data column, you can click another option: "Insert Table Columns to the Right." ...

In Microsoft Access, you can add records to an existing table that already as data and resize the columns that contain the fields and data.

Word will assign the same set of numbers to the second column. Right-click the number in the first row of the second column and choose Set Numbering Value.