I actually think it's the opposite, in English saying 'those tables' doesn't necessarily indicate distance (but often does, depending on context) while in Russian this sentence clearly emphasizes distance. Still, I think it's a good idea for the course to differentiate between this/это and that/то.
Этот и тот correspond to English "this" and "that". Check out this page: http://russianforeveryone.com/Rufe/Lessons/Course1/Grammar/GramUnit6/GramUnit6_3.htm
I am a native Russian too. But for me the phrase "вон те столы" mean that they are at some distance from where I stand, and while saying this we usually point out with the hand or use some other gesture to show that they are at some distance far away. On the other hand the phrase "вот эти столы" indicate the tables that are close by.
"То" can mean many things (particularly if you include particle "-то"), but in this particular setting we are talking about two distinct uses as a demonstrative pronoun:
"That is a table" - "то - стол" (singular masculine).
"That is a school" - "то - школа" (singular feminine).
"Those are tables" - "To - столы" (plural).
As you can see, in this use "To" is a subject of a sentence "A is B" (with A being That), and it is not modified regardless of the gender of B (and whethere B is singular or plural).
Its other use as a demonstrative pronoun is in constructions like
"Eat that apple" - "Cъешь то яблоко" (singular neuter).
In this case "that" serves as an adjective rather than a noun, and Russian "то" in this case can only be used with a singular neuter noun, as in the above example. In this use, it would become "тот" with a singular masculine, "та" with a singular feminine and "те" with a plural noun. The original sentence is an example of the latter.
P.S. If you know any German, you will recognise a strong similarity between Russian "то" and German "das": "Das ist ..." (that is ...) corresponds to the first use while "...das Bier" (... the beer) - to the second.