There are a variety of different styles of MCing an event. Many DJs talk a lot during their events. The big question is what effect does it have on the guests?
Let's first talk about volume. When we are on the microphone, saying what needs to be addressed, we should be loud. Loud enough so that everyone in the room can hear it clearly, over everything else that is happening. If the DJ is soft spoken, then no one will hear them. The DJ needs to be able to gather everyone's attention instantly, as this establishes them as the figure that shall guide everyone through the event.
If the DJ talks too much, there is the chance that not all of the words will be sparkling and brilliant. The guests get bored and tune out who is talking, turning their attention back to their salad and phone.
If you speak with fewer words, each has more impact. Guests will then be very aware that when you speak, they should pay attention.
The big things are to let the guests know what is going on, where to look and what is happening next. Nothing is worse than telling people that something is about to happen, but not telling them where it will happen.
In film, as it is a visual medium, the eye is guided to find what the storyteller deems important. If they focus on an empty chair or desk, something of significance will happen with that (or has an emotional context). For those who are Game of Thrones fans, the long window shot at the finale of Season 6 deems that something important will happen (no spoilers here!).
In events such as weddings, the same applies. The MC should direct the attention of the guests to where it is needed. Letting everyone know to focus on the doorway when introducing a wedding party, or turning towards the head table when toasts are happening.
We believe that your DJ/MC should articulate the necessities of information for the event, then let the music do the talking. Why hear someone talk during the music, when guests won't know what they say or care? They want to sing along and dance. The music already has all the energy that will get people excited and ready to expend energy on the dance floor.