Can I download large downloads on the PC? I just got my new Nexus 7 and found out that most big Android games download their data over WiFi. This is problematic for me as I don't have a good WiFi connection and most downloads freeze halfway. Can I download the extra data on my wired connection on my computer?
It depends on game. Some games allow you to download the data off phone and extract it to your SD card at the said location of the game instruction. I remember doing so for few games myself.

If the game instruction doesn't have anything like that then you've to manually find out what file it downloads from where and put it in relevant place in SD card.