GUI: how to keep data being uploaded from excel to plot them using another button

Hi all,

I am stuck with this problem. I have a GUI application which has many buttons to plot different kind of figures using the same data. I need to read data from excel and get one plot by clicking first button (I did it). Then I want to click second button to plot another plot using the same data (from excel). So how can I use this data not uploading them again??