Have a glance at following link -
Excel to HTML table conversion and code generation utility[
^]
Above link provides you information about reading an excel file.
Once that is done, you can simply copy that data into clipboard using -
window.clipboardData.setData("KeyName","my data goes here");
var contents = window.clipboardData.getData("KeyName");
Hope this works for you.
Many thanks.
Niral Soni