I'm working on a small game concept, similar to the "Canabalt" genre. I have successfully made a scroller, which passes the nametables around. However, the nametables are pre-drawn and stored in ROM. Is there a way of creating a dynamic nametable, so i can make the platforms appear randomly, while it's scrorling?

Sure. As you update nametable on per column basis while scrolling, you can construct a long random level using predefined sections. You can also create a buffer in the RAM. For example, you can fill up the column buffer in RAM with the background data stored in ROM, then impring random platform tiles before sending it to the PPU.