It says:3700W requires a 16A supply. The hob probably has internal power management setttings to allow the total load to be limited to 16, 13 or 10A which should be set during commissioning. The rating given on the box is 3700W because that is what the hob is physically capable of delivering.
If you scroll down to the 'installation' tab on this link, Bosch have shown the 3700W limit as corresponding to the 13A plug version. I suspect that is a copy-and-paste mistake from the 16A Schuko-plug version and that they do not intend a 13A plug to supply 3700W.
This hob is equipped with a UK 3 pin plug for an easy plug & play installation. The plug limits the maximum power output to 3.7 KW. For higher power output, please select a hob without plug and ensure installation is carried out by a qualified electrician
The 13A UK plug limits the maximum to below 3.7 kW - I think a mistake here in the writing.