Schematic tables [http://subtextual.org/OOPSLA07.pdf] are an extension of this idea that can handle arbitrarily complex conditionals. Unfortunately, they only work in Subtext [http://subtextual.org/], an unreleased research language. Schematic tables take advantage of the 2-dimensional visual layout of Subtext (as opposed to linear text, like most languages); it would be very interesting to see something similar in text.