First we need to store in a pdf with filename "My File". If you want a different filename each time just loop. The "par(mfrow=...) will tell R the dimensions of the plot i.e.
pdf(paste("My File",".pdf",sep=""))
par(mfrow=c(1,1))
Then we can choose a plot to print with vertical and horizontal lines; if our df has dimensions nrow by ncol:
p1<-p2<-0
plot(p1,p2,type="n",xlim=c(0.19,4.78),ylim=c(0.252,5.75))
abline(v=c(1:4),h=c(1:5))
text((1/2)*seq(1,9,by=2),rep((1/2)*seq(1,11,2),each=6),c("P","R","I","N","T"),cex=5)
Although I highly recommend you just use a package if possible such as in this short video: https://www.youtube.com/watch?v=GOQ_StD4sGA