Large index.dat folder

what are these index.dat files in this folder?
AppData\Local\Microsoft\Internet Explorer\Recovery\High

Last i checked there is 600,000+ dat files & its over 4gb. seems a waste of space just for internet explorer. With so many files is this an error or a sign something is wrong?

thanks

Welcome
I believe that folder perrtains to your browsing history. You may want to donload ccleaner and try to remove them, if you want the space.
Before taking any action, be sure that the folders that you want to delete are identical to the one shown here: http://www.winhelponline.com/blog/clear-ie8-last-browsing-session-history-using-ccleaner/

Well Ccleaner stopped at 2%. So I had enough, just used cmd to delete the lot. So far no problems.

For me these silly dat files serve absolutely no purpose at all.

If you did not want those files, you probably did the right thing. I like to solve a problem in the most conservative way, however, to avoid possible problems.