KanjiJLPT N2
Tray

tray, shallow bowl, platter, tub, board, phonograph record

Mnemonic

A carrier balances an enormous dish on his head. It's so impossibly wide and flat that guests mistake it for a tray and start piling sushi, glasses, and napkins onto it as he walks past. He can't stop — he's a carrier — so he becomes the banquet's living tray.
Additional thoughts
Picture the carrier struggling under a dish so broad it spans his whole body like a serving platter. The flat, stable surface is key — that's the tray concept.
Quick recall
A carrier balances a flat dish so wide people use it as a tray.

Details

The keyword for 盤 is tray. This kanji refers to a broad, flat surface or dish used for holding or carrying items, much like a serving tray or platter. By extension, it also conveys the idea of a flat board or base, as seen in concepts like a chessboard, a record disc, or a foundational platform. The sense of a wide, stable, flat surface underlies all of its uses.
On'yomi
ばん