How to not loose the data that is entered in the fields of the table after refreshing the page

I took the example from here, only thing I changed was, instead of default values I gave blank values. If I enter some values, I get the output working fine, but, when I refresh the page I loose my entire data.
How can I let the data that is entered undisturbed so that the user does not have to re-enter it again.

Thanks