I want to know the usage of those words.
Okay, well, in that case your questions are all wrong.
Is there any difference between the following phrase?
This is not what you want to ask.
There aren't many places around here where you can cater for fifty or so people at one time/at a time/at the same time.
If you give us an example sentence like this that you've made up, many of us will assume you're trying to say something in particular and will attempt to say it in a better way for you, sometimes not using any of the words you want to know. That's
not what you're asking of us, right?
I don't think you should be trying to make up example sentences at all. If you want to know how to use a word or phrase, find some authentic examples by native speakers, or some examples that have been made up by teachers, and study them. Don't do it yourself.
Or, if there's a thought that you have in mind and you want to know how best to say it, make sure you try hard to tell us exactly what you mean, and in what context you want to say it.