Major's paper and list is a wonderful gift. He collected a batch of words which he calls the 80% list.
If you know this batch of 1000+ words, you will know 80% of the words used in any average Ancient Greek text.
I have a low opinion of vocable cards. I don't think that kind of study leads to real learning. A person needs to meet words in contexts and take them as real communication. Flashing a word and giving me a gloss does very little for creating a meaningful or accurate picture of a word.
But in the case of the 80% list, I have different opinion. If we had a set of vocable cards with those words listed, we could become very familiar (not really learn, but recognize) the 1000+ core words. Then, when reading a Greek text, we would have a familiarity with which words are high frequency or not. Whenever we came upon a familiar core word, we'd spend time with it knowing that we'll meet it again soon. Other low frequency words, we gloss over. Maybe someday, we'll get faster at reading and see that rarer word more often. For now, let's concentrate on the core.
I was delighted to find that Anki (free flashcard software) has a deck already set up with Major's 80% core list loaded.