require("gridExtra")
a= 1:10
b=1:5
d=1:7

a <- a*0.043562
# data.frame(a,b,d)   #different length
# Error in data.frame(a, b, d) :
# arguments imply differing number of rows: 10, 5, 7

length(b) = length(d) = length(a)

d <-data.frame(a,b,d)  # no error now

quartz(height=4, width=3) # to the screen
grid.table(format(d,digits=2))
quartz(height=4, width=3) # to the screen
names(d)[2] <- "very tall\n name"
grid.table(d, equal.height=TRUE)
#grid.table(format(d,digits=2), gpar.corefill = gpar(fill="slateblue",alpha=0.5), h.even.alpha = 0.5)
pdf("tabella.pdf", height=4, width=3) # to a pdf
grid.table(d)
dev.off()