It sounds like you may have accidentally inserted extra rows below your table. Here's how you can remove them:

1. Click on the row number below your table where you want to start deleting rows.
2. Hold down the Shift key and click on the last row number in the scroll bar (the one that goes beyond 10,000 rows).
3. All the rows between the two selected rows should now be highlighted.
4. Right-click on one of the highlighted row numbers and select "Delete" from the drop-down menu.
5. A dialog box will appear asking if you want to shift cells up or shift cells left. Select "Shift cells up" and click "OK".
6. All the empty rows should now be removed and your table should be back to its original size.

If you're still experiencing issues with the scroll bar, try adjusting the zoom level of your worksheet. Sometimes, if the zoom level is too high, it can make it look like there are more rows than there actually are. You can adjust the zoom level by clicking on the percentage number in the bottom right corner of the Excel window and selecting a lower percentage.