Use this and it works great. It’s great to be able to charge both my phones and xd plus at once too.
Anker 40W 5-Port USB Wall Charger, PowerPort 5 for iPhone Xs/XS Max/XR/X/8/7/6/Plus, iPad Pro/Air 2/Mini, Galaxy S9/S8/Plus/Edge, Note 8/7, LG, Nexus, HTC and More https://www.amazon.com/dp/B00VH958F0/ref=cm_sw_r_cp_api_i_-P9uDbMJBAMG6
Charging via your computer will take forever. Do yourself a favor and get this (or something similar). I got the 5 slot one because it allows me to charge all 3 Vive Trackers and my 2 Vive Wands at the same time. I plug my Vive Tracker USB dongles directly into my computer (into a Hub; they are low bandwidth so you can plug all three into a USB hub) so I use the long cable that came with them for the wall USB charger. Gets them fully charged pretty quick.
I tend to travel with a few things that need USB power (phone, tablet, Kindle, Fitbit, etc.). I have one of these which I use both at home and for travel.
In your case, I expect it's probably unnecessary to bring a power strip. You don't usually need to charge a camera or a tablet every day, and so you'll probably not need to charge both the camera and your tablet simultaneously.
I'd get something like this, with an EU two-prong 240v plug.
I have not tried the stock charger at all.
I actually own two of those:
They are charging with about 2.8 A at 4.8V which gets the device fully charged.
There is also a thread I just stumbled upon about charging which mentions some USB-C PD chargers that might be worth a try:
https://www.reddit.com/r/GPDPocket/comments/6krvz8/official_charger_specs/
Regarding the stock Ubuntu: I would get rid of that as soon as possible as the guys at GPD seem not to have any real clue about porting Linux/Ubuntu properly.
There are several options to switch to a better distribution that most likely causes less trouble as Hans did a great job working on an awesome kernel.
You want a multi-port USB "charging" up, which has multiple high-current ports. Two of these would suffice: https://www.amazon.com/Anker-Charger-PowerPort-Multi-Port-Samsung/dp/B00VH958F0
Is this the one? It says it is not QC2.0. Thanks.