It's a very useful table on the triple.
When the runway is limiting and you are contemplating a single engine landing, if you have the performance to fly a go around from a flap 30 approach on one engine it MAY be a better decision than flap 20.
At least with reference to this table you can decide which of the options suits your situation better on the day.
If time is on your side you can never have too much information!
Jazzy