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data.table was already mentionned by @martin.R - I can confirm that its memory efficiency is its strongest point. data.table has a special syntax and mechanism to work on data by reference, therefore limiting the copy in memory. Now, it is pretty different from dplyr in syntax.
For memory efficiency in the tidyverse, I think you can try using database for your data. dplyr works very well with database connection. see rstudio website about database Using a SQLlite data.table and dplyr verbs can help you deal with big dataset.