That is every dlc and update that has been added to the game to date plus whatever other install data. You will need it to be able to play. Destiny won't ever let you sign in if you aren't up to date on the latest version. In future update downloads it may tell u that they are the same size but don't worry too much about those. That is just the way the game works and the actual total downloading will be the difference between what it is saying and what you've done previously. Not that I don't want to encourage new players and I would recommend destiny as a good game but I'm not so sure destiny will be the best choice for those with slow internet considering how much people in highly populated areas with good internet experience lag and u need to be online at all times to play at all. You may have a hard time connecting to people and may have enemies teleporting and taking sporadic damage more often than not. As for the dlc codes. They are small downloads and just give you access to the TTK and RoI content. The actual content of those dlc are included in the 31 gb download.