The dining scene in Trinidad is one of the more enjoyable ones in the country -- which, admittedly, is not saying much -- not so much for the excellence of its restaurants, but for the low-key atmosphere and a mix of both pretty good state-run establishments and paladares (private restaurants). Plenty of self-appointed guides will make their presence known, trying to lead you to an unofficial paladar; these are safe and often quite good, even if illegal (though that status has no consequence for you -- feel free to dine wherever you like).
In addition to the restaurants listed here, the state-run Plaza Mayor (tel. 41/99-6470) is an acceptable option serving a decent buffet, in a beautifully restored old home and an even more beautiful courtyard.