It can take 75A when drain-source voltage is very low.
No TO-247 device will ever handle 10A at 240Vrms - that's 2.4kW of power. You would need tens of them in parallel.
Maybe you could use such FET to PWM some 2.5kW heater, but it would take decent filtering to keep the PWM frequency from leaking to the mains supply (and also preserve close to unity power factor). I wouldn't have a clue how to design that
![Tongue :P](https://www.eevblog.com/forum/Smileys/default/xtongue.gif.pagespeed.ic.J5mTe0A2NA.png)
Another option is a PWM heater with an active PFC circuit and capacitor in front. APFC tends to have naturally "smooth" input current due to it being a boost converter, although all implementations I have seen in computer PSUs and such still employ LC filtering to meet EMI regulations.
If you don't need a lot of load current variability, just take a bunch of high power resistors / heaters of various resistances and switch them into the circuit as needed - that's the only simple solution at such power levels.