1. Open Word and insert the table.
2. Select the table, click the right mouse button, and then select border and shading in the right-click menu.
3. In the Borders and Shading dialog box, delete the left and right borders of the table border.
Click the two lines on the right, set them as hidden, and then click OK.
In this way, the left and right margins of the table have been deleted. The effect is as follows: