A huge chunk of meat is a comestible obtained by zapping a boulder with a spell of stone to flesh. As an ordinary comestible, a huge chunk of meat can be safely eaten any number of turns after it is created. Contrast this with corpses, which only last 50 turns before becoming unsuitable for eating. As such, a huge chunk of meat becomes valuable as a safe source of nutrition.
As its name implies though, it is huge; its nutrition value, 2000, is the highest in the game. In fact, the value is so high that unless you are fainting, eating a huge chunk of meat will make you oversatiated. Beware eating anything after eating a huge chunk of meat - if you are oversatiated, which is not displayed in the status bar, you will choke over your food and die unless you are wearing either an amulet of life saving or magical breathing.
Carnivorous pets, however, have insatiable appetites and no consumption limits. A huge chunk of meat will ensure they won't starve while you're occupied with activities that won't generate corpses for them.
Also, its weight shows how huge it is. Even though it is safe to eat, it is probably not good to carry it around.
A huge chunk of meat does not act like a boulder; it is a normal item that sits on the ground, and not an obstacle that you would push around.
Huge chunks of meat share the same encyclopedia entry as meatball.
Some hae meat and canna eat,
And some would eat that want it;
But we hae meat, and we can eat,
Sae let the Lord be thankit.