Yes, you can definitely shade the area between two lines on a chart in Excel. Here's how you can do it:

1. Select the chart by clicking on it.
2. Click on the "Format" tab in the ribbon.
3. Click on "Shape Fill" and choose the color you want to use for shading.
4. Click on "Shape Outline" and choose "No Outline" so that the shading doesn't have a border.
5. Right-click on one of the data series lines and choose "Format Data Series" from the dropdown menu.
6. In the "Format Data Series" pane, click on the "Fill & Line" tab.
7. Under "Fill," choose "Solid fill" and select the same color you used for shading in step 3.
8. Under "Line," choose "No line" so that the data series lines don't have a border.
9. Repeat steps 5-8 for the other data series line.
10. Right-click on one of the shaded areas between the two data series lines and choose "Format Data Series" from the dropdown menu.
11. In the "Format Data Series" pane, click on the "Fill & Line" tab.
12. Under "Fill," choose "Solid fill" and select the same color you used for shading in step 3.
13. Under "Line," choose "No line" so that the shaded area doesn't have a border.

That's it! You should now have a chart with two data series lines and a shaded area between them.