noun
small individual dining table; legged serving tray
A low, single-person table or a tray with legs used for serving meals, often in traditional settings.
旅館で、部屋に膳が運ばれてきた。
At the inn, a small dining table was brought to the room.
夕餉の膳が整えられた。
The evening meal was set out.
counter
bowlful of rice (counter)
Used as a counter for servings of rice in a bowl.
ご飯を二膳ください。
Two bowls of rice, please.
counter
pair of chopsticks (counter)
Used as a counter for pairs of chopsticks.
箸を一膳取ってください。
Please take one pair of chopsticks.
御膳 is the honorific form of 膳, often used for meals served to someone of higher status or in formal settings.
The kanji 膳 originally referred to a tray or table for food, and by extension came to mean the meal itself and then counters for food-related items. The exact historical derivation is uncertain.