Click on the top empty cell with white background to start entering the name and numbers under each month on the same row.
If no empty cells are showing to click on, please refresh the page and try it again.
You will notice that the row you're working on will be highlighted orange which indicates it's being saved automatically. Just click on it again if you need to change or edit the entry.
To delete it, hover your mouse pointer at the far right end of the row you're working on and click on the "x" button. It should delete the entry right away.
Note: You may need to refresh the page for the changes to reflect after adding, editing or deleting any entries.