Google has launched AdSense Labs which will be a new subtab under the Optimization tab with new experimental feature for you to test.
Show fewer ads will reduce minimum 10% of ads served on your site. It will prevent low value ads from being shown to the users on your site.
Inline Ads are ad units (320×100) which are inserted automatically within the mobile site while the user scrolls down.
Google Launches AdSense Labs To Test Betas!,