This is only that tricky for male nouns with the same ending in plural
der Teller male(sin) die Teller male(pl)
der Roller male(sin) die Roller male(pl)
der Koffer male(sin) die Koffer male(pl)
that doens't apply to these nouns, they have a different plural form/ending, so its easy to determine.
der Bus male(sin) die Busse male(pl)
der Tisch male(sin) die Tische male(pl)
der Ball male(sin) die Baelle male(pl)
You should know from the context. And also a good point by the previous user, is that it has no article. It hardly means, ''he has plate.'' that would sound broken, so it must mean ''He has plates'', which is similar in English. Remember that very often the structure of German is very similar to English. They, along with dutch, are in the same family of languages. Also, 'Teller' is one of those nouns whose plural form is almost indistinguishable from its singular form. For these nouns you'll have to be able to tell from the article, ( or lack of..) or if that doesn't work, simply from the context.