Hi I am developig a website and when I try to see the page source in the explorer I have houndreds of lines about this:
















 
How can I do not to show all of this? Thanks 

These are all the internal workings of ASP.NET. It's not something you have any control over. You can turn off ViewState, but if you do that, many controls will stop working like you expect them to.

 But is there another way, because the html code is very large. It would be possible to store in a session state?

Yes, you can. In cases where the viewstate gets very large, developers overwrite the viewstate mechanism to store it on the server or on a database instead of sending to the client in the html. 
 Just google "Storing asp.net viewstate in session" or "storing asp.net viewstate in database" and you should get several results showing you how. 
Tarique