1. Our picnic box was heavier than usual because we didn't bring paper cups of plates.

2. Our picnic box was heavier than usual because we didn't take paper cups of plates.
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Do we have to use 'bring' or 'take'? Are both grammatical? Which one is grammatical? What is the difference in meaning?

In these two sentences, both "take" and "bring" can be used.

We BRING something to where we are now.

We TAKE something to somewhere else.

You need "or" rather than "of" in both sentences.