The bottom line: one slide to show you ran a lot of numbers and one slide demonstrating an interesting, realistic, and more qualitative financial insight.
An initial pitch to a potential venture funder is typically 10 minutes and includes a financial projection. Since the finances are only one part of such a pitch, there is very little time to discuss any detail. A second problem is that the numbers are often unrealistic. Many pitches are for early stage developments and there is really little basis for making any sort of financial projections.
So what can you realistically and honestly do? First you can demonstrate that you've taken this seriously by showing one slide with a lot of financial data, but tell the audience that they shouldn't try to read the data, you are only showing it to "prove" you've ran the numbers for many cases. Don't try to explain financial trends with some sore of "spread sheet like" slide. Just use it to assert you due diligence, nothing more, and move off it quickly.
You can then show a second slide that proves you are being realistic and tamps down the obvious exaggerations that often go into these pitches. By exaggeration I mean the typical assumption that a new product will achieve massive market penetration. Most new products typically help a subset of patients in a subcategory of a particular disease (e.g. moderately high blood sugar as opposed to all diabetics). You might show a simple slide that shows how the financial numbers vary depending on which subsets it can penetrate. You might show a slide that discusses how the numbers vary depending on the price of the product, etc.. The key thing is to have one slide that shows you have insight into how the finances behave and you are being realistic.
Remember, you can't "prove" anything about finances in such a short presentation, so you have two goals: show you've taken finance seriously and demonstrate some insight that shows you are realistic and smart.