If a Cuban says “asere, tírame un cabo”, they're asking you for a hand.
You can use it for a physical job: “Tírame un cabo con esta mesa” — help me with this table. But it works just as well when you need help understanding something, finding a job or sorting out a problem.
“Mi vecino me tiró un cabo con la computadora.”
My neighbour helped me with the computer.
You don't need a dramatic situation. It's an everyday way of asking for a favour.
Just find out what the favour is before answering “dale”. You might be lending someone a charger. You might be carrying a fridge upstairs.