The above SNPedia link goes into greater detail, but the data come as a tab-separated file a few megabytes in size. For the older Illumina reports, the data files were about 5MB, but the newer chips may make files closer to 10MB. (550k vs 1m SNPs, respectively)
A great resource for that sort of analysis is SNPedia (check out the main page as well): http://www.snpedia.com/index.php/23andMe