Take a look at our https://www.easydatatransform.com tool. It is a drag and drop data munging tool for datasets up to a few million rows. It runs locally on Windows or Mac. You should be able to install it and start transforming your data within a few minutes. It doesn't have a built in scheduler (yet), but you can run it from the command line.

Excel Power Query is also quite lightweight. But is pretty klunky in my (biased) opinion.