Tableau apparently exports the .csv files in utf-16le encoding. So they need to be converted to utf-8.
Some of the following commands are useful (assuming the input file is utf-16le):
converting a single file:
iconv -f utf-16le -t utf-8 filename.csv > filename.csv.tmp && mv filename.csv.tmp filename.csv
converting all files in folder:
for file in *.csv; do
iconv -f utf-16le -t utf-8 "$file" > "$file".tmp &&
mv "$file.tmp" "$file"
done
find ./export -type f -name "*.json" > exports.txt
wget -i ./exports.txt