Priyanka,
In order to help You we need to have more information to work with. Which version of Excel are You running? The latest service pack installed for the Office pack. It's quite normal that large files take time to get loaded but it should not put Excel in a
hang mode. Files we work much with and that constantly grow can easily get corrupted. One solution may be to rebuild the file from scratch and in that way get a new file to work with. If there is a Anti-Virus program that scan files before open them You can
test to turn it off to see if the file gets loaded faster.
Sorry but it does not exist any general solution for large files.
Kind regards, Dennis (http://xldennis.wordpress.com/)