Wow, you have quite a few SEOs on that slab!
Some of them are affecting the slab height hence the many accurate contour type lines along it's surface.
You could try using a mesh instead of the slab. With meshes you can adjust the ridges from smooth to all defined. Perhaps that will translate with the fewer contour lines.
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"