Covid - the primary danger, according to the best science from epidemiologists and virologists, is SHARED STAGNANT AIR.
Most people are afraid of contact surfaces, but whereas some surfaces may have a significant viral load, it's all those aerosol droplets hanging around for considerable periods of time within stagnant air spaces that evidently are the primary route for transmitting Covid.
And remember that ASYMPTOMATIC PERSONS are shedding the virus all over the place.
So an empty supermarket aisle might seem "safe," but you don't know what gaggle of teens or young adults were just in the aisle 30 seconds ago who might have been chatting and laughing and emitting a big load of Coronavirus-contaminated aerosol particles that are still lingering.
This is why folks should be wearing the N95 masks (or K94 from S.Korea, 94% efficient). As i've posted before, most folks are wearing cotton masks rated at only about 25-50% efficacy.
Just sayin'....
P.S. -- Bobwins, i agree that hours at a holiday dinner in an enclosed room is a more dangerous breeding ground for Covid than just briefly popping into a supermarket for several minutes.
May you all keep safe and stay healthy, everyone.