No, there is no consistent amount of RAM and CPU consumed by the website. The platform has a maximum amount of RAM and CPU that can be allocated to any of the servers that are launched when the platform is under extreme load. The platforms scale as required, so customers do not need to be worried about whether their sites will have sufficient resources.
For example, during the night there is less traffic compared to during the day. During the night, the platform sits at a smaller level of resource consumption. Using a smaller number of resources allows the Website to not consume resources it does not actually utilize. During the daytime, when traffic increases, the platform scales accordingly.