How can I read csv extension on I Pad or à Mac book air

On the Mac any spreadsheet application should read it (e.g, Numbers, Excel, Open Office). If one of those doesn't start when you double-click the file you can open Numbers (or one of the others) first and then use the File menu Open command.

The above will convert the data so that each comma separated value (csv) is placed in a cell. If you just want to see the raw file contents you can start TextEdit on the Mac and then use the File menu Open command.