Regular Grammar and Regular Language From Wikipedia, Regular Language

All finite languages are regular.

and Also Regular Grammar, is a way to describe the Regular Language

Right regular grammar (also called right linear grammar).
Left regular grammar (also called left linear grammar).

From Wikipedia its Example :  a* b c* can be described as Regular Grammar..
but it generate infinite number of 'a's and infinite number of 'c's.
Recall Regular Language can be described by Regular Expression and Also Finite Language ..
This might be a language issue. In (mathematical) English, the statement all finite languages are regular means: if $L$ is a finite language then $L$ is regular. No implication in the other direction ("if a language is regular then it is finite") is implied.