Have you tried using the Chrome Remote desktop app? I don’t have a tablet, but I have a Chromebook with a touchscreen, and using Remote Desktop I’m able to navigate within Gramps which is running on my desktop Mac. Of course I can use the mouse and keyboard as well, since it’s a Chromebook, but even using only the touch screen I can get around well enough for browsing purposes, so I imagine it might work that way on a tablet as well. (I also have Gramps installed as a Linux app on my Chromebook; I use that as my sandbox.)