Hi @mariam_rs7, welcome to RStudio Community.
You can use the split() function as follows (demonstrated on the built-in iris data set).
split(iris, f = iris$Species)
Species is a factor variable that contains three levels (or categories). Passing this vector as an argument to f returns a list of 3 data frames; each containing only those observations for that Species. In your case, you'd use the station name variable instead (convert it to factor if it isn't).
The use of read.table() is quite simple. This video is a useful quick intro on how to use it.