It's somewhat like an "idiomatic expression". But this sentence can be used in different situations which expresses different meanings. For example, when you're about to present something on stage and you feel nervous and anxious about presenting, then someone encourages you to go for your dream. When they say "What a time for you!" it somehow means like "This would be your chance!" or "This is your chance! Grab it!" .. In another case, when someone is unlucky, you could say "What a time for you!" in a pitiful manner. And the message you're delivering is you pity the person for his/her unluckiness. Just use the right facial expression and the right intonation of your voice, and you can deliver the message rightly. :)