Thanks for your answers, Rohit. You consistently provide great responses here.

I was thrown off by this question, because Blend doesn't take a list as an argument. I finally figured out to run FullForm on the statement to see what was really happening. Aha! Table is just semantic sugar -- a "macro" in other programming languages. Blend doesn't really exist, either. It's now as clear as black and white -- or maybe RGBColor -- what's going on with this exercise. I increased the interval size to decrease the clutter:

FullForm[Table[Blend[{Yellow,Hue[x]}],{x,0,1,.20}]]

List [RGBColor [1., 0.5, 0.],
      RGBColor [0.8999999999999999, 1. , 0.],
      RGBColor [0.5, 1., 0.20000000000000018],
      RGBColor [0.5, 0.6999999999999997, 0.5],
      RGBColor [0.9000000000000004, 0.5, 0.5],
      RGBColor [1., 0.5, 0. ]]

The two takeaways I got from this:

Any sort of assumptions you have mapping other languages onto the Wolfram Language are probably wrong. The WL is a different beast.

I do not understand all the ways that mappings work in this language. Once I do, I may be on my way to being a WL Wizard. Going through many exercises is quite valuable. Stephen's "Elementary Introduction [...]" is my new favorite tutorial.

Going back to this homework exercise:

Table[Blend[{Yellow, Hue[x]}], {x, 0, 1, .20}] // Hold // FullForm

Returns:

Hold [Table [Blend [List[Yellow, Hue [x]]], List[x, 0, 1, 0.2` ]]]

Blend will take a list of 2 colors and a value x, which determines the weighting of the 2 colors to blend. I presume that providing that list with no 2nd argument gives a default blending-value of .5 -- and it's just a bug in the documentation that this one-argument option is not listed. I'll report that bug in the docs.

The real value of your comment is learning when to apply Hold to see what's going on under the hood. I see the obvious error in my interpretation of what was happening. Much more to learn! I will put those videos on my list to study, but it will take some time (and probably lots of popcorn) to get through them. Thank you again.