$ for i in A B C; do echo -e "\n*** $i"; cat $i; echo '----';  cat -vet $i; done

*** A
foo     73
bar     35
word    27
blah    23
----
foo^I73$
bar^I35$
word^I27$
blah^I23$

*** B
bar     35
yada    3
word    27
blah    23
----
bar^I35$
yada^I3$
word^I27$
blah^I23$

*** C
foo     73
word    27
blah    23
life    42
----
foo^I73$
word^I27$
blah^I23$
life^I42$