The relish tray is a lot of fun. If you get pitted black olives, those so inclined could put one on the end of each finger and eat them from there, so get enough for that. I would rather not see that at the table, but what goes on in the kitchen or the laundry room is okay by me.

These smaller dishes are good for passing around the table. I'm not sure what is in the middle of that larger dish. Surely not pickled cauliflower and carrots cut smaller. I would put grape tomatoes and small rounds of mozzarella with finely diced fresh basil or just plain cherry tomatoes.
These days the fresh vegetables are referred to as crudites, (croo-di-tay) and it is customary to provide Ranch dressing to dip them in, but back when I was a kid, folks just took a couple of celery or carrot sticks and maybe an olive and a piece of watermelon pickle and set them on their bread plate. You wouldn't want Ranch dressing on your dinner roll, so it just wasn't done back in the 50s and 60s when I was growing up.
This next one is sized for a buffet. It is from a professional caterer, so don't be intimidated, just glean from it the general idea, and in particular the attractive way things are sliced.

Here is a relevant poem from American Poet Richard Armour:
Assorted Relishes
Celery
When forced to wait and wait for luncheon,
A stalk or two will serve to munch on,
A use which would, indeed, be laudable,
If only it weren't quite so laudable.
Olives
Unless its innards are pimiento,
Each olive leaves its own memento,
And therefore, should you nibble any,
The seeds will testify how many.
Radishes
Though pretty things, they likely as not
Are either pithy or too hot.
Nor do you know, till you have bitten,
If you've a tiger or a kitten.
Pickles
Since people are of many minds
About the sundry sorts and kinds,
Some way is needed to empower one
To tell a sweet one from a sour one.
Onions
The onion eater and his brother,
Though inoffensive to each other,
Are by their diet alienated
From those who've not participated.
was a family favorite.