They allow two pages of additional information IN ADDITION TO your 2010 - 2011 K2 school report.
I think that two pages can be regarded as your 'portfolio'.
Also, on the form they already ask you a lot of information about your kid's strength and weakness, so you can save some space in your portfolio.
You can add additional information (like K2 second term report when it is still not ready) when you go and interview.
You can staple things together and mail back the form or hand it in person.
oh, sorry, it should be ONE PAGE but TWO-SIDED. that means two "faces" of portfolio information.
In the form it did not mention about certificates copies. But I did not know if they have mentioned that during the introduction section!