Suppose a use case has more that 1 way of doing it. Eg. “Buy Product” maybe done “Online” or through “Counter”. In a use case diagram I will probably use generalize? But what do I have in Event Tables?
From a system’s point of view, buying a product is the same user-initiated event whether it was initiated online or over the counter. Therefore, I believe it’s a single event. However, if you really want to mention it, I don’t see an issue of having two events that refer to the same use case. The user-event would be different (online versus counter) but the system trigger, buying a product, and its associated use case would be the same.
It all comes down to what you want to present to your reader.