Learn Swedish: Det finns ett bord av glas framför soffan. - There is a table made of glass in front of the sofa.

Yes, you absolutely can! Swedish uses compound nouns heavily, so ett glasbord is very common. Saying ett bord av glas is simply another way to express it, often used to put a bit more emphasis on the material itself.

Does av always translate to "of" in English?

Not always! English uses "of" for many different things, but Swedish is more specific. Here, av is used for material composition ("made of glass"). It is also used for non-proportional parts of a whole, like mitten av rummet (the middle of the room).

Why does the sentence start with det finns instead of där är?

Det finns literally translates to "it is found" and is the standard way to express existence in Swedish, just like "there is" or "there are" in English. You would only use där är if you were physically pointing out a location, like saying "Look, over there is the table!"