Ok, for reply correctly to OP question: "import 2000 IP address list inside MikroTik firewall"
1) Paste the list in one address aggregator:
https://tehnoblog.org/ip-tools/ip-address-aggregator/
2) put the result on some decent text editor than permit the replace the "enter" (new line / carriage retourn / anynameyouwantforthat etc.) key with
list=blacklist
add address=
do not forget space before list
3) add to the top of the file
/ip firewall address-list
4) check if the file appear like:
blacklist code
/ip firewall address-list
add address=31.13.64.0/18 list=lista_ip_facebook
add address=31.13.64.0/19 list=lista_ip_facebook
add address=31.13.64.0/24 list=lista_ip_facebook
add address=31.13.65.0/24 list=lista_ip_facebook
add address=31.13.66.0/24 list=lista_ip_facebook
add address=31.13.67.0/24 list=lista_ip_facebook
add address=31.13.68.0/24 list=lista_ip_facebook
add address=31.13.69.0/24 list=lista_ip_facebook
add address=31.13.70.0/24 list=lista_ip_facebook
add address=31.13.71.0/24 list=lista_ip_facebook
add address=31.13.72.0/24 list=lista_ip_facebook
add address=31.13.73.0/24 list=lista_ip_facebook
add address=31.13.74.0/24 list=lista_ip_facebook
add address=31.13.75.0/24 list=lista_ip_facebook
add address=31.13.76.0/24 list=lista_ip_facebook
add address=31.13.77.0/24 list=lista_ip_facebook
add address=31.13.79.0/24 list=lista_ip_facebook
add address=31.13.80.0/24 list=lista_ip_facebook
add address=31.13.81.0/24 list=lista_ip_facebook
add address=31.13.82.0/24 list=lista_ip_facebook
add address=31.13.83.0/24 list=lista_ip_facebook
add address=31.13.84.0/24 list=lista_ip_facebook
add address=31.13.85.0/24 list=lista_ip_facebook
add address=31.13.86.0/24 list=lista_ip_facebook
add address=31.13.87.0/24 list=lista_ip_facebook
add address=31.13.89.0/24 list=lista_ip_facebook
add address=31.13.90.0/24 list=lista_ip_facebook
add address=31.13.91.0/24 list=lista_ip_facebook
add address=31.13.92.0/24 list=lista_ip_facebook
add address=31.13.93.0/24 list=lista_ip_facebook
add address=31.13.94.0/24 list=lista_ip_facebook
add address=31.13.95.0/24 list=lista_ip_facebook
add address=31.13.96.0/19 list=lista_ip_facebook
add address=45.64.40.0/22 list=lista_ip_facebook
5a) save the file and import on routerboard.
5b) paste 400 lines at a time on the terminal