That means you want to get an Illustrator file (.ai) based on the .pdf you provided?
Can be done, but if your machine cannot handle the .pdf file, it probably cannot handle the converted .ai version as well.
The main issue with those kinds of maps is the total number of anchor points, text objects and clipping masks. Your file contains 362597 paths with more than 5 million anchor points and about 35000 text objects. Apart from that, there are 3247 clipping masks.
In order to make your file easier to access, a lot of simplifying would be required. And that means a lot of work, not just saving to a different file format.
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