It is a scraper.
Very nice one too.
Good size and material.
Some might say its big and chunky so it might be old, but I won't guess it's age as scrapers have been part of the lithic tool box from the beginning and though there are many varieties I'm not sure that the types can be dated (like points sometimes can) as most seem universal across the ages.
People who know Texas artifacts might tell you more.
I do know it's a great find though.