Only one Application Look Up Table has been for Sentinel-1 and thus, unlike Radarsat, there are no specific LUTs for different surface types such as sea or land. The calibration document mentioned above describes the conversion from DN to beta0, sigma0 or gamma or indeed to the original DN value prior to the application of the Application LUT. More information can be found in Sections 9.18 and 9.19 of this document: https://sentinel.esa.int/documents/247904/349449/Sentinel-1+Level-1+Detailed+Algorithm+Definition+1.6