Of Gefilte Fish Balls and Trees on Cakes

An Inwood resident was paid $15 (Canadian) a number of years ago to be a waiter at a melaveh malkah in Montreal. The appetizer was gefilte fish balls with an orange-colored sauce. The waiter was carrying a large tray of individual serving plates with these gefilte fish balls on them when the keynote speaker said something quite humorous. Not wanting to drop the tray, the waiter placed it down while he laughed. The tray apparently wasn’t too secure, and it proceeded to overturn. The poor individual who happened to be sitting there was now wearing orange trousers; the orange-and-white gefilte fish balls exited their plates and started rolling away in all different directions as if they had minds of their own. Some of them made their way to the end of the room. The waiter now really burst out laughing but not at the speaker’s joke.
For these fish balls to travel so far, they must have been well-rounded. Is there any problem on Shabbos or yom tov with making perfectly round kneidlach or gefilte fish balls?