Does the Bible give us any indication of why God created such a vast universe with so much stuff in it? We all know the universe is enormous, and this isn't the place to debate that. But why does it need to be so enormous? The only celestial bodies that could be counted as truly necessary are the sun, moon, and Jupiter (which blocks Earth from many meteor hits). Why create something 29 gigaparsecs wide when only a tiny corner of it is populated?

Does the Bible address this question?
I think any question that contains "why does this need to be so" is fundamentally flawed. The truth is nothing needs to be how it is. God could choose do it anyway He wanted to, and He choose to do it this way. 

Now, We can speculate as to why He wants it that way, but short of scriptural support it's just speculation. 

That said, Yes i think the Bible does give us some hints and here is some scripture as to the reasons the heavens are so big:


  Psalm 19 1-4 "The heavens declare the glory of God;
      the skies proclaim the work of his hands.
  
  2 Day after day they pour forth speech;
      night after night they reveal knowledge.
  
  3 They have no speech, they use no words;
      no sound is heard from them.
  
  4 Yet their voice[b] goes out into all the earth,
      their words to the ends of the world."


Romans 1:20


  "For since the creation of the world God's invisible qualities--his eternal power and divine nature--have been clearly seen, being understood from what has been made, so that people are without excuse."


So we can infer from these passages that tell us the universe is there to teach us about the nature of our Creator, that it's vastness is most likely to demonstrate the vastness of God Himself, Who is infinite and above, and beyond that which He created.