Hi, Darren
If your trying the Roadrunner file, It starts at the bottom left corner, Jog your router to the left bottom corner of your material then bring the cutter to just barley above the top of the material, Use the ReffAll button to zero all axises.
You should be ready to cut, You may need to override the feed-rate if it to fast depending on your cutter your using and the depth your trying to cut.
If it's to big for your table you can scale it down with the scale x y settings on the program run screen.
On the Tool-Path screen you can see the max size of the part size Info. top right.
Let us now how it goes.
Chip