"Good evening," said Ronan. "Students, are you? And do you learn much, up at the school?"
[Harry] "Erm ––"
[Hermione] "A bit," said Hermione timidly.
"A bit. Well, that's something." Ronan sighed. He flung back his head and stared at the sky. "Mars is bright tonight."
(Harry Potter and the Sorcerer's Stone)
What does the bold part mean? From the lexical meaning of something, it seems to mean "that’s an important thing." Yet, an example on a Korean website is translated as "one consolation in sadness," and this can make sense in the context.
What does it really mean?