Easiest way how to transform data saved in encapsulated comma separated value files (.ecsv) to XML format (.xml) would be to load the original file to some spreadsheet program like MS Excel and export the tables to XML format using File ► Save as.. function.
Such ecsv to xml conversion should be doable in other spreadsheet editor as well, sometimes you just have to manually import the .ecsv files and tweak the data in tables.