Q:

Presence of table "sqlmapoutput" in PostgreSQL database

I was pentesting a client's database and saw this one table "sqlmapoutput" in one of the user created schemas. It's a PostgreSQL DBMS. and he has no idea how it came there. There was no data in the table:
Table: sqlmapoutput
[0 entries]
+------+
| data |
+------+
+------+

On checking I found that there was a boolean-based blind sqli in his site.
So if his site was breached why will someone leave this table there?
Is there any reason for something like sqlmap to create something like this?
PS: No need to explain other issues, and just focus on the presence of this table plz.

A:

This is the result of someone running sqlmap on the database. (Specifically here) Either this is 

An honest pentester:
In this case, delete the table and fix whatever vulnerability they discovered.
Some other actor:
Consider all data comprimised. Search for whatever hole caused this and fix it, and if you have users force them all to reset their passwords.

