Wavemax is just an antenna and is advertising things it can't do. It has scam written all over it.
Tablo needs an antenna to pick up local channels but does offer some additional streaming channels. It is mainly for recording OTA shows. I have read it's very quirky.
Better cable alternatives are Fubo and YouTubeTV. Also Sling and Philo depending on what you are looking for.
I have the "older" Tablo. It is an over the air (OTA) DVR. I use it to record TV series that I want to watch. It really is not a "replacement" for cable TV. If you like to view broadcast tv (ABC, NBC, CBS, FOX) on your own time without paying for their specific streaming service, then Tablo is a good fit. You need an over the air (OTA) antenna.
I use Tablo and it works great for local channels. With my antenna setup I have just over 100 channels that are available to select from. I then use it with a bundled streaming service (Hulu/ESPN/Disney). This saves me a little money each month since I don't get locals via the streaming service.