Most likely, only the glowing parts are recording motion during the full 30 seconds, while the flash freezes everything else at the start of the exposure.

That means the tripod/table may not be the main issue: if the non-glowing parts are sharp, the overall setup is probably fairly stable. The blur is more likely from one of these:

• slight movement of the camera or subject during the long exposure
• vibration from mirror slap if mirror lock-up wasn’t used
• movement/vibration in the device itself
• reflections/refractions from glass or other reflective surfaces
• possibly dust or smoke catching the light

In a very dark room, the flash can make the solid object look tack-sharp even if there’s a little movement afterward, because the flash duration is so short. But any self-lit or glowing elements continue exposing for the full 30 seconds, so they show streaking.

Good tests: repeat the shot with mirror lock-up enabled, try turning the glowing source off, and check for reflective surfaces or vibration from the equipment itself.