@Arjun I'm not sure if I'm right but my reasoning is this -
the halting problem is if TM halts on any arbitrary input.
now, input here means a language, i.e. a set of strings. So it can be finite / infinite.
Now "any arbitrary input" doesn't tell anything about "finite/infinite", so worst case we need to check by running TM on every input. If it's finite, we will accept otherwise we roll forever. Hence undecidable.
Now here you've given explicitly that the language is finite. So, decidable.
Is it on the right track or I'm misunderstanding big time?