It will popup on the invoice in a similar detailed way.
Is that normal in the US (we operate from Europe) or should we adjust the AR report so the sales tax amount is mentioned in one single summarized amount?
Out of the box we display each line as they are attached to each line item. Simply customize the format of the SSRS to summarize by the Description, so that way you get one line for state, 1 line for county, etc.;