Most of the numbers in the link are the bodycounts of soldiers, not civilians. And the count for 'slavery' is laughably small and only deals with slaves execute

Most of the numbers in the link are the bodycounts of soldiers, not civilians. And the count for 'slavery' is laughably small and only deals with slaves executed as punishment; far, far more slaves were worked to death in the fields and mines. You really, really didn't want to be a Roman slave, unless you were an educated Greek.