
Euvola
- Camera No
- Microphone Yes
- Speakers Yes, stereo
- Connects to TV No
An 8 inch voice companion. Their own site says it has no camera. Good at conversation, but it cannot do a video visit.
You asked for four things: a camera, a microphone, speakers, and a way onto the TV. Here is how each option you sent does against those four, with the price I saw on Amazon on 30 October.
Euvola has no camera and no TV connection. The onn 4K Plus has no camera. The $80 tablet has no TV output. Details and pictures are below.

An 8 inch voice companion. Their own site says it has no camera. Good at conversation, but it cannot do a video visit.

Great on the TV, and easy to use. It only has HDMI and the USB-C power port, so a webcam needs an adapter, which is hit and miss. 2GB memory.

Good price, with a touchscreen. Its "24GB RAM" is really 3GB plus 21GB of borrowed storage, and the screen is 1280 by 800. The listing talks about USB-C for charging only.

The right shape, because most have USB ports. But many have unknown makers and may not get updates, which I would not put in a health setup. Boxes with a built in camera exist, such as the Mecool KA2, but reviews call the picture poor.
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About $115Box near $50 at Walmart, camera $63.99 on Amazon. Amazon resellers ask $98 for the same box, so buy it at Walmart.
A tablet already has the camera, microphone, speakers and touchscreen. The only question is the TV. These are the tablet routes, for homes that want them.
The cheapest tablet I found with TV output on record, and it has a 12 inch touchscreen. It is a lesser known brand and I have not tried it. Check the current price, and test one first. A tablet with this ability does the whole job alone.
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The TV shows SyncCare, and the tablet handles touch and calls. Video visits stay on the tablet screen, not the TV. Two devices to set up.

Simplest of all, and it works in a bedroom or a home with no easy TV. Casting to the TV without a cable may work, but reports show delay and dropouts, so I would not count on it for a doctor visit.
The SyncCare Android app can start with no TV, and it reads Google and Samsung watches directly through Health Connect. So a tablet can collect the watch data itself. We have run this app on phones and I still need to try it on a tablet screen.
Sometimes, and it depends on the tablet. You said on our 9 October call that you do this with USB-C to HDMI all the time, and on the right tablet it works well. The catch is that the USB-C plug looks the same whether or not video can travel through it. An adapter cannot add video to a tablet that does not have it.
So the tablet and TV path is real, starting under $200 if the Teclast holds up in testing. Most tablets under $100 will not do it. Any Android tablet you already use with an adapter is worth testing, and if you tell me the model I will check it.
On our 23 October call we talked about a companion with a camera and microphone, the RK3588H box from SunChip. Euvola is not that. The product on geteuvola.com has no camera, and they sell that as a privacy feature. If your unit looks different from their site, please send me a photo of the label.
Their site also says it is not for fall detection, emergency calling or medical alerts, and that family messaging is not available yet. Their seniors page lists family video calling devices as a separate category.
It could still sit beside SyncCare as a companion for lonely seniors. It just cannot be the telehealth device.
Device cost only, at the prices above. TV adapters for tablets are extra. Your watch, setup visits and any carrier plan are extra.
I have not tested this exact pairing, and I found no report of anyone using this webcam on this box. Google TV boxes do not all accept USB cameras, and the microphone often fails even when the picture works. So we buy one set before we buy a hundred.