Interesting. It did not accept 'the scarves are on the table'. Only difference is capitalization and punctuation which every other question ignores. Reported.
Single syllable words often take "-ak" instead of "-ok". They are exceptions, but there are plenty of them.
And the reason may be to differentiate them from the first person singular verb conjugation. For example, in the case of the word "vár". It means both "castle" and "waits".
vár-ak - castles
vár-ok - I am waiting
Another word is "kár" (something like "loss", "damage"), its plural is "károk". No verb matching this word.
In the case of "sál", for some reason it is very important to dinstinguish "sálak" or "sálam" (my scarf) from other possible derived words...