You should try reboot your router and all your devices, but start off with rebooting your router. I had the same thing about 4 years ago, a reboot fixed it for me and that was with my then Nexus phone, it took me about an hour before I decided to reboot my router.
Try downloading a ping app onto your tablet, ping your computer and your router from the tablet, then back in the following direction, that might help too, but start off with rebooting your router then your devices. IP routing tables in routers can be a pain at times, but extremely rarely is that the case.