Amy, As you noticed, tomato disease diagnosis by photo is very difficult. When I see diseases on my plant foliage, they rarely match any photos I find online. Often that is because you'll have more than one problem occurring at the same time and it is hard to separate the symptoms of one disease from the symptoms of another.

Those grayish patches on some of the leaves might indicate gray mold. The holes in the leaves could be from a pest but also could be necrotic lesions from one of the various diseases that cause them.

If you've been having rainfall and dew, I'll lean towards thinking it is gray mold or something else that is fungal in nature. I had gray mold pop up on about a half-dozen of my 100+ tomato plants after we finally had some rain fall in June (3.5" over 2 days). I removed the affected foliage and sprayed the plants twice, about 10 days apart, with Daconil and that slowed its progression but didn't completely stop the gray mold. We're overdosing on too many tomatoes here, so I don't worry and fret over the diseases too much, but that's partly because we have so many plants that we can lose some along the way and we still will have plenty of tomatoes. We've reached the time of the year that I start yanking out older, diseased tomato plants anyway so I can use their space for a succession crop of something else for the summer or fall garden. If I had fewer tomato plants and really wanted to keep all of them producing as long as possible, I'd spray my plants regularly, alternating with two different fungicides (to avoid tolerance/resistance issues) from the first day I put the plants in the ground.

Watch your plants carefully. Diseases that start on the lower leaves often progress very quickly up the plant. This is the time of year when diseases in general, and fungal diseases in particular, really hit tomato plants hard here and progress very quickly. Once plants have them, there is no real cure, but you can slow down the progression of the fungal diseases by spraying the plants with a fungicide at regular intervals following the label directions. The only way to have any chance of preventing the fungal diseases is to spray regularly from day one when you put the tomato plants in the ground.

Dawn

Here is a link that might be useful: Images of Gray Mold on Tomato Foliage