Pages is a way for you to create a dashboard or a view that allows itself to show different slices of the same data based on a dimension of your choosing.
Confusing much? Ok, read this quick sub-article here first

OK, now that you know what it does, just know that when you use pages (in the example above being day of the order date, Tableau is still fetching the data for all the dates and just hiding data for all the dates except the one page you are on.
So, does it mean an issue. Not necessarily, but like many other topics I have discussed here, this may just provide a bit of boost in terms of performance by removing pages but that doesn’t mean you remove it completely.
My job here is with this series is to educate you and let you make the best decision for your self.