classInstanceSize and vtable

[Etienne Cimon via Digitalmars-d-learn]

On 2014-10-23 20:12, bearophile wrote:
> In D all class instances contain a pointer to the class and a monitor
> pointer. The table is used for run-time reflection, and for standard
> virtual methods like toString, etc.
>
> Bye,
> bearophile

So what's the point of making a class or methods final? Does it only 
free some space and allow inline to take place?