Unfortunatley there isn't a way to have a table display numbers for the rows. However, depending on how you want your data numbered and ordered in the table you could add a rank to the dataflow.
You can actually use a windowed function beast mode assuming your have unique identifiers in each row.
This example is using the Date Dimension but you could change `Date` to your key field(s)
SUM(SUM(1)) OVER(ORDER BY `Date`)
You may need to have your CSM enable windowing functions as I believe it's still in beta.