Here's one version of the fuller list.http://www.potsdam.edu/academics/AAS/Ph ... Majors.pdf
Tied for 2nd place is Philosophy. My (non-physics) friends who took the LSAT said that they had a lot of problems learning how to answer the logic problems. So, since Physics/Math proofs and many streams of Philosophy require a lot of formal logic, this might be a contributing factor. Note that the number of Physics major that take the exam is pretty low, so self-selection does seem to be at least part of the reason too.
I do know people in Physics who take the LSAT and are aiming for a science-related law degree (e.g. patent law).