You don't directly convert dosage across species like that. The dosage they tested on monkeys was 250mg/kg, and the human equivalent would be less than that.
In this case (1000mg * 3/37)) comes out to 81mg/kg. So, if you weigh 80kg, it comes out to 6.48 grams per day.
That's a lot of taurine, but not really a crazy amount. Easy enough to consume.
The equation is from here: https://pubmed.ncbi.nlm.nih.gov/17942826/
For what it's worth, the rat equation is (X mg * (6/37))
Keep in mind that it's a loose/general guideline. Basically a starting point. But usually a quite accurate one.
https://reference.medscape.com/calculator/692/body-surface-a...