How is work affected when an object is lifted straight up instead of using a ramp?

If the ramp is perfectly frictionless, then there is no difference. 
The amount of work done in both cases is the same. 

If the ramp is real, and there is some friction, then it takes less work
to lift the object straight up than it takes to slide it up the ramp.

Alinear relationship would look like a straight line on the graph. it could have a positive negative or 0 slope. so it could be a line potentially going in any direction but it must be perfectly straight.

No it doesnt because it can be any number.