First, let's make sure your Data Source is set up correctly.  Here's
one way to do it.  (I'll assume you have Service Pack 1.  I don't know
if the interface would differ without it.)

1) Design a new form / New from Data Connection to invoke the wizard.
The following steps are all within the wizard.
2) Choose the Select Database radio button (not Web Service).
3) Select the database.
4) Select your main (parent) table.
5) Press Add Table, then pick the child table (SME9_RevHist).
6) The Edit Relationship dialog appears.  Specify the relationship
between the two tables, if it's not there already.  (InfoPath will
infer a relationship based on foreign-key constraints if you have
them.)
7) The final screen of the Data Connection Wizard will let you name the
data connection.  Pick a name then press Finish.

The Data Source area of InfoPath should now show your tables, with the
RevHist table as a repeating group of the main table.

1) If you want to show more than one document (parent-level record) at
a time, the Master/Detail control available in SP1 is the perfect
choice.  Just drag the Group for the parent table to the results
section of the surface and InfoPath will create something to get you
started.  Howver, you'll see that it puts every detail field in twice,
giving you a choice of locations.  You'll probably want to delete one
or the other.  You'll also want to format everything nicely by putting
the fields in Layout tables.  But, as I said, InfoPath will set up a
basic and sound structure to start you off.

2) If you only want one parent record, but potentially many RevHist
records, create the parent controls in the normal way (it sounds like
you have already done this), then drag the Repeating Group for RevHist
from the Data Source to the design surface.  InfoPath will pop up a
menu that gives you a choice of several formats.  Your situation sounds
like a Repeating Table would be the best.  InfoPath will automatically
create a suitable control for each field that's linked to your SQL
Server table.

You'll also need to create the fields in which the user enters query
criteria.  You didn't mention any problems with that, so I assume that
part is good to go.

Now preview your form.  Assuming you have no connectivity issues with
SQL Server, everything should work like magic!

Post again if you have any troubles, and I'll see if I can help.