The PicoScope 6 software currently exports to MATLAB v4 format.
Unfortunately, MATLAB has an issue whereby it cannot read from arrays containing more than 100 million elements when saved with this format. I am not sure if Octave or SciLab have this issue but you can try it as bennog suggested.
If you encounter any further problems, please e-mail firstname.lastname@example.org
and we may be able to provide some further assistance with this process.