Using Query could work:
Names Default To Here(1);
dt = New Table("Untitled",
Add Rows(5),
Compress File When Saved(1),
New Column("Title", Character, "Nominal", Set Values({"A", "A", "B", "B", "B"})),
New Column("Body", Character, "Nominal", Set Values({"A", "B", "C", "D", "E"}))
);
Query(Table(dt, "dt1"), "Select title, GROUP_CONCAT(body, ' ') FROM dt1 group by title");
SQL Functions Available for JMP Queries
You might also be able to do this with some split/stack/combine columns combination.
Edit: Using Transpose:

Result table:

Use Combine Columns with Row 1 - Row 3 selected:

Result:

Delete unnecessary columns:

-Jarmo