rolling board; pastry board
A flat board used for rolling out dough for noodles, bread, mochi, and other pastries.
When making udon, you roll the dough out thin on a rolling board.
Alternate kanji spelling using 伸し, which directly shows the meaning of stretching/rolling.
Compound of 伸し (のし, 'stretching/rolling') + 板 (いた, 'board').