Why does my tablet continuously scroll 'samsung' then 'samsung galaxy

I have a Samsung galaxy a tab, not very old, about a year. It continues to do a couple things. Either it comes up and tells me it is optimizing apps which ever number through whichever number. Or it gives me the two black start up pages where the first says just Samsung, the second Samsung galaxy tab a Android. Occasionally it shows me my home page, as if it's ok, but for only a minute or so and then goes back to the 2 black pages.