Translation:The black table is next to the window.
Yes. While English (and German as well, mind you) relies on prepositions to get grammar done ("next to the window"), Hungarian uses suffixes and postpositions: "az ablak mellett".
Regarding the relative positions of the subjects and the verb here, the word order in Hungarian is relatively free, and jumbling these words about changes the meaning and intonation of the sentence slightly. (Even though some of the resulting word orders might sound very odd.) This sentence here has a rather neutral structure. The black table is the topic, you want to talk about that one, and "next to the window" is in the focus position, right before the verb. This is where the black table is.
You could also say "Az ablak mellett a fekete asztal van." Then you're talking about the space next to the window and that it's occupied by the black table.
Or you could go with the most-close-to-English structure: "A fekete asztal van az ablak mellett." It sounds a little odd and carries the meaning that there exists a black table, and it's there, next to the window.
Hmm, there are hints on what each word means if you point your cursor at the word. Or tap and hold on the word if you're on mobile. Alternatively you could get the help of a dictionary. There are a lot of online dictionaries out there, or you could buy a book if you prefer that. You can also ask Hungarians you might know to help you. :)
"At" the window sounds a bit weird, as if the table was leaned against the window. "By" would be the better choice in this case.
But to be strict, mellett doesn't mean "at" or "by". Mellett means "next to" or "beside". That means, the table is not just anywhere close to the window, but at the side of it. Not directly in front (possibly blocking the window), but a bit left or right from the window.