This is the common English term given to a crisp, small, cucumber-type melon that is called in Chinese by the far more poetic name “tea melon.” It is packed and preserved in a sugar syrup and is a beautiful translucent white-gold. Finely slivered, it is a delicious garnish for cold poultry and fish salads and is used regularly as such by the Cantonese.
The best brands I have found are Mei Chun and Tung Chun, both packed in clear glass jars. More frequently seen canned brands have no sparkle whatsoever. Opened, the tea melon will keep indefinitely in the refrigerator, covered with the packing syrup.