Yes, it is possible to add multiple comments to a single cell in Microsoft Excel. Here's how you can do it:

1. Select the cell to which you want to add multiple comments.
2. Right-click on the cell and select "Insert Comment" from the drop-down menu.
3. Type in your first comment in the comment box that appears.
4. To add another comment, right-click on the cell again and select "Edit Comment" from the drop-down menu.
5. Type in your second comment in the comment box that appears.
6. Repeat steps 4 and 5 to add as many comments as you need.

You can also use keyboard shortcuts to add and edit comments. To add a comment, select the cell and press Shift + F2. To edit a comment, select the cell with the comment and press Shift + F2 again.

Note that each comment will appear as a separate box when you hover over the cell with your mouse. You can also view all the comments at once by selecting the cell and clicking on the "Review" tab in the ribbon. Then, click on "Show All Comments" to see all the comments in a list.