there is a table "users_entity" which holds the basic information of a user (name, username, email).

My question would be why are you using PHPMyAdmin to get this information? There are tools on the community like Profile Manager which allow you to export information about the users.

I want to make a graph in GEPHI so that has to be generated in the CSV format , which only PHPmyADMIN can do , do you know any plugin that can export information in terms of CSV or GEFX format ?

i dont know how soon you want it but i too have been trying to do this...let me see if i can get it done before end of next week...but follow @ jerome Bakker's advice; profile manager exports to csv