Setting aside health effects, I'd question the economic viability of 'socially distanced' show with a lot fewer punters.
Given that the organisers will have extra stress and cost, they're unlikely to be able to cut table costs etc, which means that traders are faced with the same entry cost, plus their own extra cost because of covid etc, knowing there will be fewer people present to buy stuff.
Certainly if I was asked about running a show my advice would be to forget it. However much I want to go to one.