Script To Rearrange Sharepoint

So I took a job at a very large company (15+ sky scrapers worth of computers) and their IT infrastructure is an absolute nightmare. Their entire network is on DHCP (yes you read that right), they had no consolidated asset list, next to no chain-of-custody for IT assets, and and their network is split onto 3 separate domains (currently consolidating).

The first phase of our project had us inventorying all of their IT assets, which has very recently been completed. Unfortunately they didn't want to fork over the cash to do the db in SQL so instead we have 30,000+ lines of assets in flipping Sharepoint in a single table.

So now I am being tasked with creating views for this Sharepoint and surprise surprise we've exceeded the list threshhold lol.

I think there may be a solution here, but I wouldn't even know where to start for sure. The first column in sharepoint is a "Site ID" which is basically just a numeric value that corresponds to a department within the company. There are currently about 1700 Site ID's and the growth of that list has all but completely halted.

So my question is simple, how can I go about making a new table that is nothing more than a column list of each of those Site ID's, and then create a new table from each value and move every line with a corresponding number in their first column into a new table of the same name. Basically a PK/FK one-to-many relationship.