Combinations are trades constructed with both a call and a put. There is a special type of combination known as a “synthetic.” The point of a synthetic is to create an options position that behaves like an underlying asset, but without actually controlling the asset. Why not just buy the stock? Maybe some legal or regulatory reason restricts you from owning it. But you may be allowed to create a synthetic position using options.
The contract specifications are specified for one contract, so the tick value shown above is the tick value per contract. If a trade is made with more than one contract, then the tick value is increased accordingly. For example, a trade made on the ZG options market with three contracts would have an equivalent tick value of 3 X $10 = $30, which would mean that for every 0.1 change in price, the trade's profit or loss would change by $30.