RALPH:  The word table comes from the Latin word, tabula, for a writing tablet, originally made of wood. Of course if you take a large flat piece of wood and add some legs, you wind up with a piece of furniture that we now call a table.

SARAH:  We still partially retain the original sense of table, in expressions like table of contents, or multiplication tables, both of which would be lists on such a tablet.

RALPH:  So when Hamlet says, "the table of my memory", he's invoking the metaphor of the memory as a writing surface, on which memories are written and can be erased.  The Latin expression, tabula rasa, erased tablet or slate, refers to the idea that our minds are empty of content when we are born - a clean slate - and that all our thoughts, no matter how abstract, arise from sensations and experience. This is an old philosophical idea, but one which will gain prominence about a hundred years after Hamlet, in the writings of the English philosopher John Locke.

SARAH:  We should also note that it's just right at the end of this monologue that Hamlet uses the term again, this time literally referring to a notebook or tablet, when he calls out for his tables.  The metaphorical notebook of his mind is here supplemented by the literal notebook that he writes in to bolster his drive for revenge.