"Spiritual service"
I was interested in the term "spiritual service" because that term might be key here.
While Major Tom doesn't view his readings as such, some people do see it like that. Some people for instance, view Reiki as something purely practical or even scientific, while there are others that give it a more "other wordly" vallue... such is also the case with Tarot. Now it isn't about how the practisioner feels about it, but how the client, potential client or event orginisation feels about it. In this case the one responsible is the mayor, he feels that Tarot has something to do with spirituallity and wether you agree with that or not is not important.
There are many people who believe Tarot is more than just cardboard and pseudo psychology and if that is what you believe, then the next step would be admitting the "use" or in any case the excistence of external energies. Admitting to the excistense of those energies, wether spirits, angels or demons contradicts some excisting Religions. So, in black and white terms... the Tarot reader indicates there might be something other than God influencing our world, while there will be people visiting the market that believe God is the only power that influences the world. Thus, reading Tarot cards can be viewed as proselytising, in a same way for instance as a spiritual healing, a Scientology character profile or a medium channeling your grandmother.
If belief A is right, and belief B says A can't be (completely) true, then B is Proselytising...
Still any idiot can sell bibles and talk about them in a stall, which in this case should also be exclude from the market... as would anything that has to do with religion or spirituallity however remotely related like...
Budha statues, bibles, books containing any form of personal believes, jewelry containing any other imagery then the complete abstract, DVD's and CD's which might influence any view on religion, meat (pork is not allowed by Judaïsm and Islam, while cows are considered holy by Hindu), items that are red in colour, items that aren't red in colour...
You might be proselytising; Satanists, Wiccans, Asatruar, Sufi, Sikh, Jews, Scientologists, Jehova's whitnesses, Amish or even Jedi.
Catch my drift? Everything in a market can in some way be connected to faith, if it can be connected to one religion it automatically says another religion might be wrong... proselytising everywhere....