100 ounces is the size of one contract, but the quote is in dollars per ounce. See the spec on CME and NYSE Liffe. Thus, one futures contract is for 100 ounces of gold, at 100 * $1174 = $117,400.
Similarly, for crude oil on the CME, the contract size is 1,000 barrels, but it's quoted in dollars per barrel. I don't know why FT shows the contract size for gold, and not for crude oil.
The contract size and the amount per quote differ because the the contract size is going to be what makes sense to actually trade. 100 oz is a standard size for gold bars, and people don't want to take delivery of a single ounce. It's easier for people to talk about the price of an ounce of gold though, as opposed to an arbitrary amount like 100 oz, which is really more of a detail. You see similar things for options, where it's quoted as the price per underlying share, but a contract is 100 options. So if a call option trades at $2.50, buying one contract costs $250, and is for 100 shares.