You can read in a list of .gif filenames from the relative data directory like this...
filenames <- list.files(path = "data", pattern="*.gif")
Similarly you can read the files names into a Tibble by leveraging your operating systems file picker, like this...
library(tidyverse)
library(fs)
files_table <- as_tibble(path_rel(choose.files()))
If you have the filenames in a tibble, you can leverage the purrr package to iterate over each file...
files_table %>%
filter(str_detect(path_ext(value),
fixed("csv", ignore_case = TRUE))) %>%
mutate(data = map(value, read_csv)) %>%
unnest()