Lysine and arginine are amino acids. Amino acids are the building blocks of proteins. Long ago, someone noticed that herpes grows better in cell cultures that have more arginine and grows not as well in cell cultures that have more lysine. Then someone else figured that this might also apply to the diets of humans who have herpes. Both of these amino acids are present in proteins, but the ratio varies from food to food. Nuts and seeds and grains have a higher proportion of argnine, and animal proteins have a higher proportion of lyine. Nuts and chocolate are two common foods that contain a lot of arginine.
If you really want to try it, you need to look at a chart that shows not only the lysine and arginine content, but also the total protein content, and then you have to do some math to figure out how much of each you're really getting.
A more sensible and practical approach would be to keep a diary of what you eat, how you feel, how much sleep you get and what herpes symptoms you get. Then play with it if you think you see some correlations.
As I mentioned in another thread, I think there's probably something to it, but I don't think it's as simple as it's usually presented. Otherwise, I wouldn't get away with eating as much chocolate as I do.