Hi Sorry for the delay replying, I've been at work.
A company is a registered company in the UK (mostly private limited companies, plus LLPs, PLCs etc), geocoded I geocoded the company address found on companies house.
Address sharing is huge: about 3.9M of the 6.4M companies share their registered address with at least one other. The record is 71-75 Shelton Street in Covent Garden, with 101,007 companies registered at it. 128 City Road is next with ~53k.
If you click an individual location on the map it should tell you how many companies are at that location.
I've less interest in the map part, more curious about where you're going with companies and railway stations (and other UK GIS data sets).
The back end analytics and cross products of various sets gets interesting for teasing out things interesting on their own, some with the potential for commercial product, forensic tracking, scam busting, etc.
If so, how many companies have the same address & what's the greatest number of companies with the same address?