Would something like this
nb = EvaluationNotebook[];
SetOptions[nb, NotebookEventActions -> {{"KeyDown", "l"} :> FrontEndExecute[FrontEndToken[nb, "ScrollPageLast"]], {"KeyDown",
"f"} :> FrontEndExecute[FrontEndToken[nb, "ScrollPageFirst"]]}]
work? If you press l you go to the last slide and if you press f you go to the first slide...
Probably it is better to use these keys as they are not normally part of Wolfram Language Input:
nb = EvaluationNotebook[];
SetOptions[nb, NotebookEventActions -> {{"KeyDown", "'"} :> FrontEndExecute[FrontEndToken[nb, "ScrollPageLast"]], {"KeyDown", "§"} :> FrontEndExecute[FrontEndToken[nb, "ScrollPageFirst"]]}]
Cheers,
Marco