I've read about teachers who dress and act like the historical or literary figures about whom they are teaching. This strikes me as a highly imaginative and potentially very effective approach to teaching. Merely coming in to class each day in a distinct costume would probably make that class more memorable, although to really pull of a completely dramatic approach would require a great deal of talent.
I assume that you are talking about instances in which a teacher does something dramatic to teach the class, rather than doing more typical things like lecturing or having students read.
If so, the major benefit of this is that the students are more likely to remember the lesson that is being taught. When something is taught in a dramatic way or an unconventional way, it is easier for the students to remember. This is particularly true if you can teach the subject matter through some sort of story telling in the way that a movie would. This is much easier to retain than lectures or textbooks, with their dry and factual style, are.
Of course, there are drawbacks, the main one of which is that it is very difficult to get a lot of content into a theatrical performance. They're better for getting a few main points across.