The tablet is a rebranded ULogic WP8060U .
Works well with other applications, but has trouble when trying to enter "Freehand Annotations".

Freehand annotations are perfectly OK when using a mouse, but when using the tablet, the curve drawn acts close to a pen with a string attached out to the border.
Sorry that's the best description I can give. What happens is I manage to draw a very small segment, then at some random point a line from the pen to the border is drawn.
This results in an arc that looks like it has tons of spikes running oput to the border.

Thanks Mouse

Can you verify that the graphics tablet is correctly calibrated? Another thing you could try to do is use it in mouse mode with Okular.
You can use Krita (part of Calligra) to verify if your graphics tablet is calibrated correctly.

I have not used krita, gimp, or any other ink using tools recently, when I have used them in the past it has been OK. I have been using xournal quite often and it has been working fine.

I also tried presentation mode and inking is OK. Of course once I leave presentation mode the ink goes away. I don't know what you mean by "mouse mode". I'm talking about "review mode" when I press the Freehand ink button.

Upon looking further ot seems that I get a "skie" whenever I pause and at start. If I draw smoothly the pen goes smoothly.

With regards to mouse mode - I was referring to the mode where a graphics tablet will act more as a mouse instead of a tablet.
As the issue appears to only occur under a certain set of circumstances however, this indicates it could be a corner case bug in Okular.

If Krita / GIMP are working correctly, please file a bug report at bugs.kde.org regarding this.

This bug also affects me, is there some bug report or a workaround?
It also occurs, if I move my mouse slowly and change direction suddenly

Anyhow this seems to be a bug of Okular, wich this thread seems to be about.

My Wacom Intous S had the same problem.
But using the buttons in the pen I calibrate the number of points and become well.
The real problem is the number of points...