As for what you are asking, in this case (quite frequently used) they imply the same thing.
The fact that somebody knows the multiplication tables
[Que alguien] sepa las tablas de multiplicación de memoria
is equivalent as the fact, that such person
Se sepa las tablas de multiplicación
But you should not generalize as to say that this Spanish construction of saber[se] has a memorizing meaning, though. It implies that sense in these cases of the multiplication tables, —since it's a practical, almost mechanical technique to recall them quickly—, but it may carry other meanings (such as self-awareness), in the same way that knowing implies but exceeds memorizing.
se sabía rodeado y decidió actuar arremetiendo contra ambos sin dudarlo
[The man realized he was surrounded and decided to act, charging against both]