Sampling from a data table in R

I'm new to R and I would like to know how to take a certain number of samples from a csv file made entirely of numbers in Excel. I managed to import the data to R and use each number as a row and then take random rows as samples but it seems impractical. The whole file is displayed as a column and I took some samples with the next code:

Heights[sample(nrow(Heights), 5), ]
[1] 1.84 1.65 1.73 1.70 1.72

Also please let me know if there is a way to repeat this step at least 100 times and save each sample in another chart maybe, to work with it later.