I think that was @cwinske 's point. h(x) should have showh not showf.
Yes, you should be able to do the table on the same slide, using the code in slide 9’s graph CL in slide 8’s CL (minus the error of “graph1” instead of your component’s name “g1”, but you won’t need the background if you combine slides anyway).
Also instead of three different functions you could use one:
function(`f`): parseEquation(input.latex).differenceFunction("x","y")
And in the graph:
0=f(x,y)