I would say it's almost certainly just a typo and is meant to say 3 MB to refer to the CPU cache size which is something that would frequently be mentioned when listing a laptop's specification.
Checking the Intel product page for the i5-7200U it does indeed list the cache size as 3 MB but sites like NotebookCheck will often give more detailed information and you can see that there are actually three separate cache 'levels' not just one.
The typo theory would be further supported by the fact that the v and b keys are adjacent to each other on most keyboards.