If you have worked steadily during your studies you will have avoided the need to start carrying out large amounts of new work at exam stage.
You cannot read every note you have ever made or books you have used and hope that the information sinks in. Whilst remembering is an important aspect of exam revision you should avoid learning in an unstructured manner. In order to apply your knowledge you will need to have it clearly structured in your mind.
Picking out the key topics and summarizing the information will help you clarify the wider subject areas.