What free tools or templates do you use to turn telecom data utilization export CSV's into useful data?

I don't do this very often, but I'm helping someone understand their Internet usage. The only data they have are the ugly DataUtilizationExports from their telco provider. In the past, I would work through a spreadsheet to put together trends based on business hours using 2-3 months of data. Honestly, while this works, it takes way too long and I was wondering if there was a better way for one off's like this.