Note Spreadsheet Tools for Data Analysis, part of the GeoGebra Spreadsheet Quickstart.

It is possible to simply copy data from a spreadsheet application to the spreadsheet view in GeoGebra, see the following slides for a simple example. The data used is mentioned on this Statistics page. From Hodder Education, the data set has 93 records on cycling accidents. (GeoGebra Data Analysis as a pdf file or  PowerPoint: GeoGebra Data Analysis.)

This post on Regression includes the use of GeoGebra for data analysis.