Thank you for reaching out to us via our online Answers Forum. I can understand that the remote appears very small on the bigger tablets and there are a few work arounds for this. You can zoom in on the remote by using an outward pinch. This will blow up what ever part of the remote you want to see.
You can also control the cable box using the alternative control funtions available.
I would also check out these helpful articles:
The Sling Media Moderation Team