The screen shot just barley shows a hit of a bit more just “my only option”. Not that drive capacty is an option there’s the check box for Auto-Delet Recordings. So you might be on the setting tab and mis-interputing what you see.
But as @sgnadeau points out, there should be a menu option in the upper left - the stacked bars, looks like may you have a “gear”.
A subscription is only “required” for guide date, and extra recording options, adding features making tablo easier to use. (if you’re still undecided, you can subscribe) monthly and not jump for the life all at once)
“Usually” the first web app screen is the Primetime tab from what I recall, but who knows for sure, maybe this is just a friendly reminder.