Maybe it was simply a pragmatic solution to ensuring enough valid juros were available?
nm. Ninja’d by experts.
The U.S. equivalent would presumably be asking something like “Have you ever been convicted of a felony?” According to Wikipedia, 31 states in the U.S. exclude felons from serving on juries.
The list of specific summary offences (“non-felonies”, in U.S.-ese) seems a bit odd, but I guess you can’t expect that average potential juror to know which is which.