Is it possible to connect several powerful consumers to one machine?

You can connect as you want! But in this case, you need to connect everything not only through the machines, but also through the RCD. Why did you indicate two power values ​​in the electric oven? Such powerful consumers always connect to a separate line and a separate circuit breaker. This is necessary for safety, so that in the event of a short circuit in the heaters of your oven, the machine line is knocked out. RCDs need so that in case of current leakage through the heaters of the oven, washing machine or water heater, you will not be killed by electric shock! Therefore, the preservation of the health and property of your and your neighbors depends on the choice of the connection scheme.