午餐 is lunch (午 is noon, and {餐 is meal), and 肉 is meat, so 午餐肉 is lunch meat, i.e. spam. 蛋 is egg, and 三文治 is the loanword for sandwich, so altogether 午餐肉蛋三文治 is lunch meat egg sandwich.
About This Dish
A Hong Kong-style sandwich with pan-fried spam and scrambled egg.