If you work in a corporate environment, then the Word document format is still pretty ubiquitous. Personally, I've switched to Google Docs for most of my own documents, but I still receive a couple of Words docs from others via email every day. And it's common request from clients of our Services team to generate documents in the Word format in a particular corporate template, but also including output (tables and figures) from R. 

You can generate Word documents from R using knitr and pandoc, but the Word output it generates is pretty vanilla. If you need to generate a Word document based on template with fonts, logos, etc. you might want to take a look at the R2DOCX package by David Gohel. It lets you start with a Word template and then with a few lines of R you can:

• Replace keywords in the document programmatically (think: “AUTHOR” or “DATE”)
• Insert formatted tables based on R data (including support for coloring table cells, controlling fonts etc.)
• Insert R graphics as charts
• Programmatically insert paragraphs, line breaks, etc.

Take a look at the Word document embedded below as a sample of the output you can create. The base template file was created ahead of time in Word, with the author, chart, tables and charts inserted with this R script.

To get started wth R2DOCX, you can install it from GitHub with these R commands:

install.packages("devtools")
devtools::install_github('R2DOC', 'davidgohel')
devtools::install_github('R2DOCX', 'davidgohel')
require(R2DOCX)

You can learn more about R2DOCX and download the source code at the link below.

GitHub (David Gohel): R2DOCX