"Take profit" here is the pips that price will have moved to the predicted direction. If you trade right on release time, set your TP to this number to max your profit. I refer "Volatility" to the degree of up & down movement, how violent the price is. But I often think they're interchangeable. If volatility increases, you should take more profit.
At the time I created the calendar, I focused on my news trading system: Open trade just minutes before data is release and set SL and TP to the expected volatility. I designed the calendar based on the assumption that everyone knew the system. And so the future chart, for example, is not described as "future 5M chart which starts ticking when the data is released".