Small tattoos are tattoos people usually start out with. They are testing the waters as far as the tattoo process goes. They don’t want the tattoo to be too large if it is their first one because they want to see how it feels wearing a tattoo.
When they get more comfortable with having a small tattoo sometimes that small one extends into more tattoo designs making a large design. Small tattoos are also for people who may work in a professional setting that like the art but want to be able to conceal it by location and size.