"At this moment, the cats are eating."
Translation:Vào lúc này, những con mèo đang ăn.
As a Vietnamese, I understand what you mean with "tại thời điểm này" but it just sounds a very little unnatural :D
Normally when you talk about plural things, you use "những". Here we have "cats" which is plural so "những con mèo" is reasonable.
No worries :) That happens all the time while studying foreign languages.