The new refractometer is very handy and there are very good online converters. But, sometimes I don't want to run over to the 'puter, find a URL, and type with my wort-covered fingers. Printed tables are handy and they won't short out if they get wet.
Here are some tables to quickly convert from brix to SG. My preference is page 2 - Brix to SG, where you read UP. The refractometers go from bottom to top and it seemed natural to put lower readings at the bottom. The columns roughly correspond to light, normal, and heavy Original Gravity.