Can somebody explain to me why I can polybase reference an azure BlobStorage as external table but not an azure StorageTable? Did I missed it some where in the documentary? Its some kind of ironic for me if I don't missed it and it is really not possible.
I created a uservoice idea, please vote if you found this is a feature that is missing:
Azure Table Storage can store more No-SQL structures so is potentially more complicated than your average flat-file. Even different rows can have different schemas as per this example. Polybase on the other hand is optimised for highly-structured flat files and loading high volume at high speed. It has a fairly simple interface where you can set the file type, separators, a few failure options, but not much else. So in answer to your question, Table Storage data could potentially be more complicated than could be optimised for high speed loading via a simple interface like Polybase.
However this is not a problem as Azure Data Factory can import from Table Storage:
Polybase has recently been extended to support Azure Data Lake Store (ADLS). If you feel strongly about this, you could post a feedback request: