Kent and the coast end of May

This is a very general question. Have you read the RS guidebook for England? Is there a particular reason why you chose Kent and the coast? How many days will you be in England? Will you be using public transport or will you have a car?

It would help to list your interests, budget, number of and relationship of people, travel method, duration of stay.

Why are you going to Kent yet asking for things to do? Kent is not an obvious choice of destination and is not on the well worn path of English locations that most tourists follow which suggests a particular reason for choosing it. That's not to say that Kent isn't worth visiting, it is but it's not the "Oxford, Stonehenge, Cotswolds, Bath" route that many tourists blindly follow without questioning why.

what type of transport you are using, do you intend to be here during the Late May Bank Holiday, and what sort of things you like to do would help.

WW2? Orchards? Vineyards? Gardens? Shopping? Cobblestones? Country houses? Castles? ???

Help us help you

I appreciate the list, Nigel.
I will be coming off a 9 day bus tour of SW England with a group of 24. We will be visiting or driving by TV series sites, such as, Downton Abbey, Doc Martin, and Poldark. We'll also spend the night at Bath.
I suspect I'll be tired of touring sites by bus window at the end.
I have personal reasons to see SE England. I'll probably take the train from London down to Margate and spend 4 days before leaving the UK.
I'm amused by those who pooh-pooh areas of their country to visitors. I did the same when a couple from Ireland said they've been to the USA but only went to Disney World. I understand the attraction, however, I would rarely recommend Florida to international travelers. Florida is Gods waiting room where retirees from the NE go.
I stood on the beach in Ireland and waved to Scotland. I want to stand on the beach in England and wave to France. Crazy, perhaps but to each their own.

I hope my comment (above) didn't sound like pooh-poohing. I only wanted to get a better understanding of your interests and motivations for choosing this region. Your wish to stand on the shore and wave to France sounds great!

I haven't been, so don't have specific suggestions, but you might want to read the book The Bone Clocks. The first part has to do with the Kent marshes. https://en.wikipedia.org/wiki/The_Bone_Clocks

No-one's pooh-poohing your choice to visit Kent but it's an entire county and difficult to provide recommendations without the further information we requested. I only queried Kent, not because it's not worth visiting (it is) but because it's a place rarely on the tourist map so I assumed there was a particular reason for visiting.

If you want to wave to France and be able to see so you can see if they wave back the best place is around Dover. On the cliffs above the town you can get a decent view on a clear day. Other than the very interesting Dover Castle (both above ground and most especially the tunnels below ground) there isn't a lot else of interest in Dover. Bill Bryson's descriptions of the town are about right, but he paints a much rosier picture than its current state which isn't rosy at all. Spoiler alert- He didn't like the place.

Will you be driving after the bus tour and Margate or taking buses and trains?

Margate is on the water but more distant from France and some other Kent attractions. Will you be making day trips from there or is that just one night?

I haven't seen much of Kent at all, but I took a very enjoyable day-trip to Canterbury. The historic center is very picturesque (ignore the other visitors, of which there will be a lot), the tourist office runs walking tours, and the cathedral is magnificent. Upstairs (literally--no elevator) at the cathedral is a nice stained-glass museum that allows you to see some historic glass at eye level.

Thank you everyone. I appreciate your advice and suggestions.
I find it helpful when people can say why this or that town, vista, sight-seeing attraction, etc. is interesting to them. I have eclectic tastes so to tell you I want to see what sells to tourists wouldn't necessarily be true or satisfying to my sensibilities. You may suggest something I never would have imagined was a possibility or an attraction.
On a recent trip, the group visited a brewery but I went on my own stroll through town and found a cheese shop that also sold unusual, to me, beverages. The shop keeper and I chatted for a bit. I bought a few items and later, shared my afternoon with the group. In Venice, I was the only one of the group who went to the opera sampler. I rarely follow the crowd.
I won't have my own transportation in England and most likely will be on the train. If there are bus, van, or taxi options, I'll check into that.