memory board

NOUN
12 LETTERS · STARTS WITH M

memory board is a valid 12-letter word worth 21 points in Scrabble and 23 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
M3E1M3O1R1Y4B3O1A1R1D2
3 + 1 + 3 + 1 + 1 + 4 + 0 + 3 + 1 + 1 + 1 + 2 =21 PTS
DOUBLE WORD → 42TRIPLE WORD → 63
MEANING

What does memory board mean?