I have tested copying the data for an entire row and the data for a single cell. At the end of the copied text there is only "10 13" values added. Actually the 1013 pair of characters is the signal for the end of a line and beginning of another one.
Would you please confirm whether you test with the latest version - Q2 2013? I have run the test SQL query on the text I copied from this online demo and at the end of the copied value there were only one '10' and one '13' value. Would you please try to reproduce it with text copied from that demo?