One variant on this advice comes if you aren't interested in viewing the data outside of LabVIEW (e.g. textfile, Excel, etc.), but just want to be able to save and retrieve it and use the minimum amount of storage space.
In that case, it's probably best to save and retrieve the data in binary format. Check out the "Write Binary File.vi" and "Read Binary File.vi" examples that ship with LabVIEW (Help >> Examples >> Fundamentals >> File I/O >> Binary File Examples).
Regards,
John Lum
National Instruments