Don't know to be honest!
I have watched the most haunted team do it, on several occasions, with some what seem to be good results but...theres always a but!
is the table moving due to spirit help or does the subconcious really help?
the best one I saw was the MH team, in Holland, they only had one finger on each and one camera was focused on the base of the table, the table did move slightly, up and down rather than side to side, I watched the episode and then MHExtra where they showed several camera angles at once and you could see that the table was lifting up and down just very slightly and they only had one finger on it
you cant as far as I know lift a table up with one finger
so...I dont know