Add daily fixed cost to table

Hi

I dynamicaly get cost data from Azure that have multiple rows per day with various products/cost. 

Now I want to add the cost of a 3.part product that we pay monthly (e.g. 300$), so i can use it in my visuals.

What is the best way to add a new daily row into to the Azure table with a cost of 10$ (300$/30 days)?

Thanks

Kim