Use printf
:
printf '%-20s|\n' 'abc' 'abcdefghijklmnop'
Saída:
abc |
abcdefghijklmnop |
No seu caso:
printf "| %-20s | %14s | %4s | %10s | %7s |\n" \
"$(echo $i | cut -d '_' -f 1)" "$number_of_backup" "$sizeInGB" "$type" "$pidType"