Abstract: An improved user interface having a data table for input and display of real-time data on a handheld device. The invention is applicable and useful or other computer devices with a limited screen display such as personal data assistance and other hand held electronic devices. An embodiment of the present invention is an application program on a graphing calculator or other computer, which allows the user to display and modify a two dimensional grid of real-time data. Similarly, other embodiments include the same user interface functionality in a ROM software application package that is executed on a graphing calculator or other handheld device.