They are both used.
As far as I now, il tavolo refers to the piece of furniture, while la tavola refers to a table for dining (not as a piece of furniture).
So, il tavolo works, what about la tavola? I seem to recall having seen both?
Looking in one dictionary its says il tavolo is a table or desk, and la tavola is a table, plank or board.
I keep hearing tavoRo instead of tavoLo. Which is the correct one?