i'm not sure about keywords but if you would like to get report for specific page your can create a channel for that page and get report
If you have added various sites to your adsense account, you can get easily information about your traffic from different types of sites.
i know, but the question was how to find what content (pages or keywords) of one site generate the most adsense revenues. Creating one channel per page for 1000-page website is kinda crazy...
channels of google adense, https://www.google.com/adsense/support/bin/answer.py?answer=9868&topic=152