If you are not willing to increase your RAM then consider Memory Management for sessions in your asp application.
In most cases, not all visitors to a site need to have a session associated with them. In a lot of scenarios when I visit a website, I don't need it to remember me while I am browsing the site. If in your code you have avoided any session specific behavior, such as setting a session variable or retrieving the session ID, ASP engine will play nice and destroy the session it created for the request at the end of the request for you.
This issue arose in one of our stress tests where we observed a small increase in memory consumption on some of the pages. On these pages, we were setting the Locale ID for the session using <%Session.LCID = some_value%>. I was puzzled to see that removing this directive from the page put an end to the increase although there were more script code on the page, which were seemingly unaffected by what I thought at the time to be a memory leak. It turns out all we were doing was altering the ASP session state, which in turn caused the ASP engine to keep the session alive in contrast to other pages which did not have session altering code.
Source