I see this as being about the tributes being called away to the games as sacrifices for the sins of their fathers (so to speak). They're lambs because they're young and innocent (for the most part); the line, "come away to the slaughter/To the ones appointed to see this through" further reinforces this idea because the game makers are the ones whose jobs are to make sure kids die in the slaughter of the arena.
I see this as being about the tributes being called away to the games as sacrifices for the sins of their fathers (so to speak). They're lambs because they're young and innocent (for the most part); the line, "come away to the slaughter/To the ones appointed to see this through" further reinforces this idea because the game makers are the ones whose jobs are to make sure kids die in the slaughter of the arena.