I'm sure I've read about someone doing a survey on these vaults....Mayhaps google would help?
Industry wise, vaults are unlikely to contain anything like corperate secrets. Most secure storage ina bank is for ease of access and uniquness of items. This means, mostly, paper and antique items. From memory:
1: Firstly, it's unlikely more than 80% of the boxes are occupied, unless they hit a depository (Long-term storage, this is where a company will lease out a certain amount of secure storage, with only access to 2-3 members of the company. Hit one of these and your runner's lives will be measured in hours. KE or Lonestar will pull out the heavy tactical response with the matrix and magic being very chilly.)
2: Private correspondance, mostly love-letters (if male) and tax stuff (If female) (Statistically, lots of these. After the 60th version of "dear Susan, last night was magical..." your runners will shoot you. Or start laughing at what they called "raunchy pictures" back then)
3: Medical information - mostly for insurance purposes - and legal crap. Land deeds, stock certificates, maybe even bonds.
4: Wills! You'll find up to 10% of the boxes will be rented by legal firms.
5: Mundane things, like passport copies (credsticks, ho!)
6: Family heirlooms. Sure, it's a ratty-ass gold necklace with some bulldog inside the photo broach to you, but to them, it's of great aunt May, before goblinizing...
7: Guilty secrets, adoption papers, paternity suites, long-lost relatives, family feuds. If you want to get weird, ask your runners why a retired honourable salary-man wants a box of nothing important back...one who doesn't want word of his ork daughter getting out, 'natch?
8: And the
nasty stuff. Blackmail, snuff, and worse. If you want them to dig through these, be prepared to scar your players. There's a reason why a lot of people get bent out of shape if a large and secure vault is knocked off, and it's not because deputizing a will takes half a day.
Hooks: a retired Cardinal wants to hire them to recover an unopened box. (Low fruit, I know, but weird.) You can make it seem terrible, then turn out he was hiding the secrets of his superiors. Or have him be the ever-so-kindly choirmaster of lost souls.
9: Weirdness: ~ 1% of the boxes will have something odd, but not really explainable. So:
The signed Elvis record.
The video of Jetblack playing for a bunch of runnners 3 years after his death (Name the run, kids:))
A small book of herbs and possible remedies (thank you AH, most excellent hook)
Some very old prototype ware (lost when the owner was unsuccessfully (ie: kill) extracted, still an amazing breakthrough in essence-loss reduction, perhaps..?)
An old firearm, pre-awakening (an anchient crime with a smoking gun?)
A mummified foetus, wrapped in swaddling-cloths with pointed ears...or evidence of goblinization, medical tag still attached, pre-awakening
Clues to Concrete Dreams "Lost Recording" (I'm pretty sure they missed a year in their annual release schedule, I tossed together a Halloween-Treasure hunt/haunt about that one.)
Music, interrupted by sounds of alarm, and then really creepy noises. Can screams for help that never come. (make a tape up, get some doom sounds happening with elevator music. Play it for your players.)
The will of Howling Coyote, as entrusted to McBean. (from Prime Runners, SR, god, 2?)
Post-it with "Hastur, Hastur, Hastur" written on it.
GPS co-ordinates of another Dunkie lair. Incomplete, but with some nice toys in it? "Note to self: must change password. Open Seasame is too cliched. Must be wary of <note runs out of space>"
A pre-columbian jade axe head.
Silver-tipped ammunition.
Keys to another deposit box.
Prototype nano-forge.
Ivory thimble.
Blood-encrusted scissors.
A single piece of chalk, wrapped badly in cling-wrap
The "Ring" video. (Have their comlinks/PS's call after the video's been seen.) "7 days." <Click>
A sword, rusted and uncared for.
A pile of kugerands.
Underwear.
A dessicated and dry severed finger.
Herbs
A packet of "Heat-and-pop" stove-top
A persec with nothing but ppppppppppppppppppppppppppppppppppppppp<ad infinitum) on it.
A small silver box, engraved with initials, in which you find a clump of pubic hair, neatly wrapped ing a ribbbon
And so on and so forth

-Tir.