Is your Dell tablet running Android 4.4 OS or higher? 4.4 is the minimum for Roon(5.0 is recommended.) Roon’s Remote software can be quirky on some tablets. I have intermittent problems with the Remote software on a Lenovo i7 Helix running Windows 10, but no problems with a Google Nexus. Roon lists supported tablets somewhere on its site. Is your Roon core on a SSD? It should be.
I can’t see much purpose using Roon just for Tidal, except possibly
for the Roon DSP engine. This does upsampling, custom digital filters, and parametric EQ. Upsampling requires a fairly powerful PC at the core. The value of Roon is in managing a large library of ripped CDs and hi-res downloads. It does that in spades. I also use Tidal inside of Roon, but only add select titles to my Roon library.