Suzanne, in reality, your finish is probably nothing more than the wax and a solvent in the lemon oil. The wax CAN have good protection against water but not much against abrasion. Other waxes are better but you probably do have a reasonable start. I suggest that you apply a paste wax finish with Johnson's Wax every so often. With the amount of use your table gets, it may be necessary to do this one a week for a couple of weeks, and then maybe once a month. Other products like Pledge will have silicones in them that will create worse problems.
At this point, it will not be possible to apply a film finish and stand much chance of it lasting. Sorry.