I didn't see that you had a picture of the table loaded when I was surfing on my phone. Good thing that you're not going to compare steer numbers with anyone else, you'd also need to compensate for your inch marks being in a straight line and perpendicular to the edge of the table.
Once the stop pad is on it, I'm pretty sure I'll be able to read the steer at the point that it first touches the marks at the leading edge of the tape ... the lines are just long at the moment and I didn't plan on reading them at the far end of them.
Beside I don't have the tools to calculate and draw the proper curves, working on a lunch money budget lol