Squid Balls are not the testicles of a squid, but rather cooked balls of puréed squid, often served as part of a Dim Sum selection.
The raw squid is puréed, mixed with some flour and spices, formed into a ball and then steamed or fried.
Language Notes
If you hear or see someone referring to squid testicles, they’ve either made a typo or are being funny. They mean tentacles. For the record, a squid has a single testis: it is an internal one, and it is more like a long tube.