You don't need to double space between the rows. As long as your lines end with CRLF or LF.
Check your text editor. I have mine set to UTF-8 and CRLF
This works:
[width="75%",align="center"]
[cols="30,30,40"]
|===
|Part | Type | Information
|2N2222A | NPN | BJT 600-800 mA
|2N7000 | N-Channel | MOSFET 300 mA
|2N3904 | NPN | BJT 200 mA
|TIP120 | NPN | BJT Darlington Pair 5 Amp
|220 Ohm | Resistor | 1/4 Watt
|1000 Ohm | Resistor | 1/4 Watt
|===