[borges]

Well, if S is your hourly std. deviation (when playing one table). Then
S^2 (S times S or S squared) is your variace when playing one table. If
you are multitabling N tables. Then since the variance scales linearly....(since
the variance of the sum of independent random variables is the sum of
the variances) your variance per hour would be N*S*S...or the standard deviation would
be S*sqrt{N} (S times the square root of N). So yes, if you are multitabling
4 tables your hourly standard deviation would double (but your win rate
would quadruple).

Hope this helps.