Translation:The apples fall out of those bowls which are on the table.
What do you expect, if English doesn't make a distinction :)
amelyik is singular, amelyek is plural.
In German, you would also make a distinction between der Teller, der auf dem Tisch steht and die Teller, die auf dem Tisch stehen even if in English it would always be "the plate(s) which is/are on the table".
I think the explanation at the bottom of the lesson overview explains this nicely: https://www.duolingo.com/skill/hu/Directional-Conjunction-2
'which' is not only used for unnecessary information. It depends on the comma whether it is unnecessary/redundant (non-restrictive) or important (restrictive) additional information. i.e. restrictive and non-restrictive side clauses.
I don't like eating apples which don't taste good. (I like eating apples in general, but not those that don't taste good.) I don't like eating apples, which don't taste good. (I don't like eating any apples, because (to me) they don't taste good.)
I'm sure there are better examples out there, but that's the best I could come up with within a few minutes.
Sidenote to the sidenote:
Sorry, I know this is a Hungarian course here. I just though some people might find it helpful for this exercise.
It looks like the person who wrote that explanation (at the bottom of the lesson) is the same as the one who came up with all those crazy sentences in the exercises.
Or, to put it their way, that person, who wrote that explanation, is that same one, as that one, which came up with all those crazy sentences in those exercises.
Either way, I would approach it with some caution.
I am not a Hungarian speaker, but I asked someone about this. As he said it is not "from those/that" because a subclause is following. The subclause defines the noun already a bit closer so there is no need for the 'pointing' articles. But again - I am not a native speaker, I have no idea if this is right or not.