I’m not sure why you linked me to a chart of mammals. Hunting mammals may be a good way to feed a small population, but as you point out it’s not feasible for the entire world.
Three fourths of all animal biomass is aquatic (fish, crustaceans, and mollusks), together accounting for 30-40 times more biomass than humans. Mollusks are the smallest component, but they still have more biomass than all the mammals in your link put together. Fish by themselves account for seven times as much biomass as all animal livestock put together. And crustaceans have even more combined biomass than fish.
I’m not even suggesting that people eat only fish. Rather, by including some fish in our diet we would reduce our reliance on farm-grown vegetables.
Globally, humans currently eat an average of 20 kg of fish/crustaceans/molluscs per year. That might be a bit too much, but I have no doubt that we could sustainably eat 10-15 kg per year.