There are five columns in the paytable because your winnings depend on whether you played 1, 2, 3, 4, or 5 coins. Note that there's a bonus for the Royal Flush. Instead of winning 1250 coins (5 coins x 250), you win 4000 coins. So you should always play five coins ("Max Bet") when playing video poker. If you can't afford to play five coins at a time, switch to a lower-denomination machine. (Yes, this is opposite of our advice about slots, and that's because the penalty for not playing max coins in video poker is greater.)
Despite the importance of finding the best machines, most players don't. That's why casinos can offer both decent and lousy machines in the same casino and be confident that gamers will still play the lousy ones. They have to keep some good machines, otherwise they'd lose all the players who know what they're doing. But most of the machines will be bad, and most gamers will play them anyway. Heck, in Vegas even casinos and supermarkets have video poker, with absolutely terrible paytables, but people will still play them rather than going across the street to a casino where they can get seven times better odds. Go figure.