Easy peasy. You've probably heard the term "fork" paired with lightning before, haven't you? Just like you've heard of a "fork in the road." A "fork of lightning" is a common phrase – almost a cliché, even, so it doesn't sound entirely creative.
And we get the "yellow" part pretty easily, too, since all of the lightning we've ever seen is either yellow or white.
But wait a second. Dickinson might be taking that old phrase about a "fork of lightning" literally. Is she talking about the kind of fork you eat your salad and spaghetti with? Maybe.
Do you know that children's picture book The King Who Rained? It's a pretty punny book that takes common phrases and makes them literal. Check out this picture of the cover to see a king who is raining. (Get it? "Reigning"?)
Now let's take Dickinson literally. Imagine it's a dark and stormy night. You hear thunder rumbling and then see a sudden flash as a golden dinner fork falls from the sky and spears the ground.
We usually think of lightning as beautiful and majestic. But when you compare something as big as a lightning bolt to something as tiny and unimportant as a fork, it's just a little bit funny.
From Tables in the sky
A fork and now a table? Ooh, it looks like we are supposed to take Dickinson's phrase literally.
If the lightning is a huge, falling fork, it has to fall from somewhere, right? And where do forks usually fall from? That's right – dining tables. Really big ones, in this case.
By inadvertent fingers dropt
This is where things start to get a little hairy. OK, so the lightning is a yellow fork that came from a big table up in the sky. Now, someone dropped (or, in abbreviated Dickinson-speak, "dropt") it accidentally ... but who?
The awful Cutlery
When the speaker says "awful Cutlery" here, she doesn't mean "awful" like, "Ew, what tacky silverware!" She means "awful" in its original sense of awe- or dread-inspiring. This is the most amazing and terrifying fork you've ever seen.
We're not being a smart-alecks, and neither is the speaker; we're starting to get a feeling that this poem isn't just about lightning being huge and fork-like, but maybe the lightning as a symbol of something even bigger and more awe-inspiring.