10 Billion KG

Yes - a lot things, in fact. Primordial black holes are small - probably around the size of an atom's nucleus, which is ranges from 1.75×10−15m (hydrogen) to 15×10−15 m for heavier elements. What's smaller than this are electrons, quarks, strings, and the Planck length.

A stellar black hole would be the remnant or end product of the normal sequence of evolution of a star; the word 'stellar,' which simply means "pertaining to a star," disambiguates the type of black hole from those that might have been created through other processes, for example, primordial black holes thought to have been created in the early universe, or highly energetic particle collisions, etc. A stellar black hole is thus a black hole created when a massive star has exhausted its fuel and collapsed under its own gravity overcoming all outward forces which might resist collapse.

It's possible that some "primordial" black holes were created from local density fluctuations immediately after the big bang, though we don't know of any that are so small that they could only have been formed in this way.