Well, if you followed the other tutorials, you know that the first value commented in an event, it's your type. Therefore, the value 18 is to "interact and receive."

The second value is set to Spriteset and sprite that the event will take before and after opening.
! Chest is spriteset
4 is the sprite in spriteset
! Chest is spriteset
4 is the sprite in spriteset

What happens when it opens, it is that the event happens to look up, and spriteset, this is the "animation" of the open trunk. Therefore, the condition is that there is complemented with server interaction.

The reward!
Well, the third value is the reward that comes from the chest. Note that there are several numbers, but they mean only 2 items.

Each item is composed of four values. They are kind, db number, quantity, and refining.
We will translate for you to understand better:
Value 0 - 2 - Number of rewards
Value 1 - 1 - Item type (1 items are the tab "items")
Value 2 - 1 - Item number in database
Value 3 - 10-10 items of that type and number will be delivered
Value 4-0 - The item is +0
Value 5 - 1 - Type of items (1 items are the tab "items")
Value 6-1 - Item number in database
Value 7 - 10 - 10 items of that type and number will be delivered
Value 8-0 - The item is +0

As in this case there are two rewards, we had to write two items, but it was just one, the text die worth 4.

Simple, right?