# Paste the data into a string:
data_string <- "     Filename         Fc
Q5161811.04    20.36
Q5161811.04    20.46
Q5161811.04    24.17
Q5161811.04    20.20 "

# Use a fileConnection to read the data into a data frame
the_data <- read.table(file = textConnection(object = data_string),
                       header = TRUE,
                       sep = "",
                       stringsAsFactors = FALSE)