No, it was religious education. I don't know the exact situation in Novgorod at the time, but throughout Europe in urban or near-urban areas it was common for f

No, it was religious education. I don't know the exact situation in Novgorod at the time, but throughout Europe in urban or near-urban areas it was common for first sons to inherit the family business, while subsequent sons would undertake some sort of religious training, either monastic or not.