How would you connect this Samsung Tablet to the Sonos Port? I’m mostly in the Apple ecosystem, I use AirPlay 2 to connect music on my iPad to Sonos (a Sonos One, but the device just needs to accept the signal, it could easily be a Sonos Port). 

Both Apple and Google have removed the ability to use their tablets as a drive, likely for security reasons, so you’re unable to use the tablet as a simple ‘library’ setup for Sonos.

Most tablets, at least these days, only have a physical headphone output, if the connection isn’t via WiFi. You end up with warring volume controls, between the volume of the tablet, and the volume of the input (sensitivity) on the Port’s line in…too easy to mess one or the other up, and end up with ‘bad’ sound, especially for those unfamiliar with your setup (you may be fine, but guests could really mess it up). 

Google has chosen (insert conspiracy theories here, I have my own) to not allow Sonos to use the ‘casting’ ability, which would function much like AirPlay 2 does in my case.
 

So, ultimately, I’d recommend either just leaving the music on the Apple, and not using it for anything else, or moving the library to an NAS (Network Attached Storage) device, and setting your Sonos to access its music there. This is my solution, but I’m not always able to do that, which is why I sometimes use Apple Music with AirPlay 2 on my iPad to get the sound into the Sonos system. Of course, once it is in the Sonos system, I can send that music to any ‘room’ on my system…something I frequently do, especially right now with baseball broadcasts which are not on a ‘radio’ feed, accessible by one of the radio plugins inside Sonos, but available on a web page. 
 

I used to use a Bluetooth Receiver/Transmitter (RX/TX) linked to the Sonos Port line-in/out and play my tablet/mobile audio via Bluetooth pairing it to the RX, but now just use an Era device these days as an RX, but I still use the Port output to the TX and link that to my Sony Headphones.

Playback control on the headphones is via Alexa built into the Sony product, I just ask Alexa to play on the Sonos Port and it outputs the requested audio to the headphones. It’s just not the best setup for TV audio (due to lip-sync), but works fine for any music sources.

Thanks, I’m sorry I wasn’t clear.

I’m just outputting from the tablet via the RCA line-in.

I was just questioning of my Samsung Tablet A8 ouputs decent quality across the line-in.

I do need some device with a monitor at the Port as my wife is playing music programs from a number of websites via web shortcuts.

I’m trying to decide to run with the tablet or puchase an inexpensive laptop or chrome book.

The quality will likely be up-to 16 bit 44.1Khz (CD quality) so you should be fine.