What does pipe("pbpaste") look like? It's hard to diagnose why read.rable() is doing that without being able to see what you're trying to have it read.
Hi, and welcome to community.rstudio.com! Without knowing what your data looks like, it's a little hard to answer your question. To help you get the right help for your question, can you please turn it into a reprex (reproducible example)? This will ensure we're all looking at the same data and code. A guide for creating a reprex can be found here.
I suspect there may be something about the way your data is formatted that's causing the output you see.