The two important boxes in that block are:
Devices: one eth one Wifi .. so like you said, it seems the PC and the TV are connected.
The next important info box is on the last line, second from the left.
Content Sharing: File Server enabled and DNLA enabled.
I reckon plug in any USB storage device(whatever you have available for now).
Plug it into the USB port on the router
That title called Content Sharing looks like it's clickable, which probably opens a box to get into some settings.
Somewhere in there should be some configs to set file system type and so forth.
It'll be easy to set up.
Once you do that, whatever device you plug into the USB port on the router should subsequently be seen in Windows Explorer under either or both, the Network index, and or some media area(maybe). . but for sure under the Network index, under the name of the router.
eg. a screen cap of my Windows Explorer index
network screencap.jpg
Note under the R6300(my router) there is a folder called TV Drive. This is a folder I created on an old USB HDD connected to my router. There is no drive letter assigned(I haven't mapped this one) so it onlyu comes up under the network list, under the device that hosts it(the router).
This is accessible by the PC and also by my TV under the media menu.
(it's old recorded tv shows and stuff like that).
I can easily send any file to that folder via Windows Explorer ... copy/cut/paste/send to(if I set that up) .. etc
So if I send something to that folder on the PC, in a few moments it's there for the TV to see it too.
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Above that is a listing for the DNS-327L. This is my new 'emergency' Network Attached Server(NAS) box. (I had to get something to replace my dead main photo archive storage drive, and this was basically it)
This is also under the Network tab in the index too.
Note it's a two bay NAS, where I have two HDDs installed. One is for all media(Volume1) and the other is set as my (now) primary backup for photos(Volume2) .. the replacement for the dead USB3 drive I used to use.
Both those two NAS drives have been mapped to Windows, and also come up under This PC .. just like your regular drives do. Vol1 is Y:\ and Vol2 is X:\
Again, with this system, you can easily send files to(and from) any of those drives via Windows Explorer.
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Basically what this means, is that you can use any such drive device(on the router) as a back up location if you feel it's needed. Otherwise, just use something like that as the primary media storage.
The bonus is that any device can write to that drive(if you set it up that way) .. ie. allow all rights.
So for example, lets say you're browsing stuff on the tv and you download something to view, you should(in theory) be able to save it to the networked drive .. and then later be able to see it on the PC if you like .. nd vice versa.