One of the things that is useful about kable() within the knitr package is that anything you can structure into a data frame can be printed as a table. I used this technique to create figures to compare actual vs. theoretical values for the Exponential Distribution assignment in the Statistical Inference course (sample values redacted).
The code to produce this table looks like:
Statistic <- c("Mean","Std. Deviation")
Sample <- c(round(theMean,2),round(theSd,2))
Theoretical <- c(5.0,5.0)
theTable <- data.frame(Statistic,Sample,Theoretical)
rownames(theTable) <- NULL
kable(theTable)