read_csv fails to import tables unless at least 3 semicolons

[miebach90]

When importing data using read_csv I came across a case where the reader completed but did not import any tables.
It turned out that this was caused by the empty lines splitting the tables. my csv file only had one ';' on the empty line where the reader seemed to be expecting 3. c.f. line 658 and 457 in startables.py