If there is any way to Change column width by user in run time like we did in excel to change A,B,C and other Column Width      

Item widths can be set programatically using set_item_property. You'd need popup menus to issue the commands.
But if you increase the width of the 1st column (item) you'd then need to move all the other items to the right

change their x_position) to accomodate it)

.The code will get very messy very quickly.

https://community.oracle.com/thread/2546396