you can't add a combo box to a table.
You can select "lookup wizard" as the type for a field.
That's how, but sooner than later you will find this is NOT a good idea.
I must admit that the idea of having a combo box linked to a field,
especially a key field, is intriguing.
When I switched from Revelation (Pick) the inability to enter a value in a
key field and have it bring up that record was missed both by me and my
clients as I switched them over.
Turns out in the long haul that not having the previous record and the
original record available was even more painful.