When you authenticate you Mobile apps using Windows Azure Mobile Services you may want to add the user id in your table row. This way you can later filter them while reading. This sandbox filing would give a portal experience to the end user. Now this can be done at the client level but the “Server Script” is the most elegant way to do it because it can hide the code from user to do injection.
During insert you may write
While reading you also need to filter out.
So your table level data security is implemented.