Hi Harish,
Marketo will track them and log their activities, but it will not provide you with this info until the leads fill out a form, either in the same session or in the future, from the same browser. But if they do not convert, you will never have this data. By definition, these people are anonymous, so even if you would know, the usage would be limited. You still can use the web page activity report, with a "activity source = anonymous visitors" setting, but it will not give you the clicks.
Marketo will also track the activities and attached to known leads in the DB and having a cookie attached to them or if they visit the page coming from an email sent from Marketo.
At the end of the day, Marketo cannot replace a web analytics tool such a google analytics... Both are complimentary and should be used together.
-Greg