330 calories for 3-4 thin slices of beef sounds reasonable until you realise those slices weigh maybe 90g total and a third of the calories (100 kcal) is literally just absorbed frying oil. The beef itself is actually decent protein, 24g per serving, which is solid. But dendeng is one of those deceptive lauk items where you see a small pile of meat and think you're being good, then you grab another serving without thinking. Worth noting this is a ballpark estimate as hard calorie data for dendeng specifically is thin, so treat 330 kcal as a useful working number rather than a precise lab result.
What really moves the number is how the beef was cooked and how much sambal they pile on. Standard crispy fried dendeng (the plain version without extra sambal topping) is where you get the 330 kcal base. Dendeng balado is specifically the crispy version dressed with a balado red chili sambal on top, which pushes it closer to 350 kcal. The dendeng lambok, the softer moist style, drops down to around 280 kcal because less oil is absorbed. Portion control is where most people slip up lah, because dendeng goes so well with plain rice that you just keep reaching. If you can stick to one serving (those 3-4 slices) and pair it with a big scoop of veg instead of extra rice, the protein-to-calorie ratio is actually pretty decent for a lauk option.