OpenRefine (ex-Google Refine) is a powerful tool for working with messy data, cleaning it, transforming it from one format into another, extending it with web services, and linking it to databases (1)

For journalists its very helpful on finding isolated cases, anomalies and general filtering of information. Its is also ideal for putting separate tables into one  (as long they have the same column names).

The official page of the tool provides links to download and several tutorials. Even using your browser to function, Open Refine runs locally in our computer, so your data will not be hosted elsewhere in the cloud.