i've not a plastic container with dividers. mine is not this large, but to give you the idea:

it's aimed at fishing for the lures etc..
I have a few of the rca to 1/4", a few 1/4 to 1/8 (mono and stereo), the impedance converters that have xlr to 1/4" .. headphone splitters, as well as an exacto blade (box cutter) with electrical tape... I bring that on every gig I do just in case something screws up.
one piece of advice I have is.. if you ever buy the RCA (female) to 1/4" (male) adapters... DO NOT get the cheapest ones... skip past the one dollar ones and get the 3 dollar ones.... on the cheap ones after a while the 1/4" end will fall apart... they come apart at the rings (ie: the tip will fall off) and guess when that happens? when its' in the jack... which is a total pain to remove as the jack's pin will be holding it in. I had to take apart a mixer once because of that.. both of those cheap ones the same thing happened.. lucky for me the second adapter from that pair broke by me stepping on it when it fell on the carpet. now I use the gold plated ones if I need to.