Read Tabular Data (readr)
Read flat/tabular text files from disk.

Read excel files (.xls and .xlsx) into R (readxl)
The readxl package makes it easy to get data out of Excel and into R. Compared to many of the existing packages (e.g. gdata, xlsx, xlsReadWrite) readxl has no external dependencies so it’s easy to install and use on all operating systems. It is designed to work with tabular data stored in a single sheet. Readxl supports both the legacy .xls format and the modern xml-based .xlsx format. .xls support is made possible the with libxls C library, which abstracts away many of the complexities of the underlying binary format. To parse .xlsx , we use the RapidXML C++ library.

Quick Wraps 2 (qwraps2)
A collection of (wrapper) functions the creator found useful for quickly placing data summaries and formatted regression results into .Rnw or .Rmd files. Functions for generating commonly used graphics, such as receiver operating curves or Bland-Altman plots, are also provided by ‘qwraps2’. ‘qwraps2’ is a updated version of an package ‘qwraps’. The original version ‘qwraps’ was never submitted to CRAN but can be found at https://github.com/dewittpe/qwraps. The implementation and limited scope of the functions within ‘qwraps2’ (https://github.com/dewittpe/qwraps2) is fundamentally different from ‘qwraps’.