Method One: The cell right menu, select the Format cell, and then click the Edge option, on the left side of the draw diagonal line is OK. This adds a diagonal line to the slash.
Method Two: The following to learn about the Excel table to add a slash in the way to make a number of diagonal lines.
1, click the View menu, select Toolbars, and then select the drawing option.
2. After drawing tool, select "Straight line". The mouse changes to a cross. Move it to the beginning of the slash you want to add, hold down the left mouse button and drag to the end position, release the mouse, Excel table add slash to draw.