A super simple test on Ubuntu I did back in November got me a 14mb executable consuming about 23mb of ram and about 38mb once the app was full screened. I'm pretty happy with the size considering the smallest runtime I can get with jlink around 40mb. I have also found GraalVM devs to be very responsive to issues on Github.

I should note I am using Haxe here instead of pure Java, so a pure Java app might be a few kilobytes smaller.

Screenshot: https://imgur.com/3otiHA2