My first thought was, since people then and people now are not significantly different outside of the technology available, what are the chances these are just legitimately tchochtkes, decorations, and just little trinkets made by people feeling bored and artistic for the purpose of simply making something they thought was "these are just pretty dang neat and fun to make"?

I feel like a lot of stuff found in tombs, burials, and other things often are ascribed a lot of religious significance when in fact it could just be things they were buried with by family because they liked owls, or because it was something a grandchild had made for their grandma? I'm not saying all or even most of the artifacts ascribed religious importance by archeologists are such objects, but there simply must be a handful that are.

I mean, memes are nothing new. And even today, there are millions of people who just enjoy decorative knickknacks that look like owls (just to use the OP as an example), so why should we consider ancient people's to be so different? Maybe a certain culture thought owls were cute, or neat, or maybe the animal did indee hold a religious or superstitious significance which led people to make owl tablets because they found them to be nifty?

Honestly, I think the authors make a reasonable argument about the toys. Kids have always made toys out of things they've found in the woods or whatever, e.g. ever picked up a stick that made the perfect sword or wizard staff? Why should this be so different? What if someone commonly saw owls and thought they were just pretty darn cool, so they tried to make an trinket that looked like the animal they enjoyed?

Just a thought. I'm certainly not an archeologist or anthropologist, but I do wonder how many artifacts like these are ascribed far more significance than their crafters ever intended.