Meshes and Surfaces - Autodesk AutoCAD 2013 Practical 3D Drafting and Design - page 430

Note
The SURFTAB1 variable controls mesh density along revolution and the
SURFTAB2 variable controls mesh density along curved parts of the original sec-
tion. Straight parts have no divisions.
The EDGESURF command
The EDGESURF command (no alias) creates a mesh from four linear objects that
define a closed boundary. The command starts by displaying current values of the
SURFTAB1 and SURFTAB2 variables and prompts for the selection of four curves
with coincident endpoints, by any order:
Command: EDGESURF
Current wire frame density: SURFTAB1=20