I personally have a 20$ TP Link myself... I'm only using Wifi for laptop, smart phones and tablet so i don't care how fancy it is. My PC is connected with an UTP RJ45 cable so there is a minimal ping as possible for multiplayer gaming.
Its working 4 years now and like 1 or 2 times per year there is some hangs and need of reset.. so i consider it good enough
I'm surprised your internet provider didn't supply modem/router with wifi already.. its a standard now.
I don't want to suggest anything... if its only to get your tablet a wifi than any router with a RJ45 port as a WAN input and some build in 4 port switch will do.
I guess one of the cheapest solution will be TL-WR740N.. its about 20$.