but more to the point, dhl will likely charge you an arbitrary tax amount before they release your tablet. standard shipping is always the better choice

This old urban myth raises its ugly head again. DHL neither assess the value of the item, nor decide how much tax is due nor profit from the tax collected. DHL have no choice but to act as collection agents for the government. Same for the other couriers. Same as shops and businesses have to collect VAT on behalf ot the government. Same as employers have to collect income tax on behalf of the government.

However, these threads always turn into a series of vitriolic posts bashing the couriers when the amount of tax due is assessed and ultimately received by Customs.

You are wrong. It is no myth. I imported a lot of Iptv boxes. They were supposed to be 0% import duty. When they arrived I was charged 10% + 7% vat. I could not understand why I was charged the tax. The international tax code was clearly displayed on the box as were the contents. On studying all the paperwork carefully I found that on the delivery notice from DHL they had used a different tax code. I looked up what the code was and found out that the small box contained, according to DHL, 10 TV display projectors!! This bore no resemblance to either the contents or the tax code displayed on the box. DHL had just made up a code to make sure they could claim some tax off me.

I needed to import some more of the same item and the company I bought from would only send by DHL so expecting the worse I went ahead and ordered but made sure the outside of the box contained a good description of contents that matched exactly the wording in the tax schedules that said the items were 0%. This time the goods arrived and I was charged 5%.

My last experience with them was when a sample of the same type of equipment was sent to me from Canada. As it was only one item the overall value was very low. So this time they charged me 20%!!

When I complained to DHL in Bangkok they said the only people who can import at 0% are companies with an import license for that product. This is a wrong. They also had no explanation as to why each shipment of the same item was charged at a different rate or why the code was changed on their delivery notices.

I don't see the answer. Did the OP get his tablet?