While I could make a preferred choice that would be suiting my needs and not yours. Those are three good picks though. Just some things to add to that 'minimum of 3GB RAM' aspect
-- Which version of Android is it running and/or can it be upgraded. Picking one with the 'best' hardware specs is one thing but if one will be getting OTA patches for a longer period of time that might be something to consider.
-- microUSB or Type-C port? If you have multiple devices all using one or the other, you might not want to add in an odd-one-out. Of course if you already have microUSB <> Type-C adapters around this is a moot point.
-- AMOLED vs IPS LCD. If you watch a lot of streaming content on your tablet aspects like screen resolution and pixels-per-inch are something to account for. As for the AMOLED vs IPS LCD debate, there's no shortage of advocates for both sides on what's 'best'. Be it visual appearance to battery life issues, for me it's a matter of having both side-by-side to make a direct comparison, or I'll just be lazy about it and say both are really good.
