The following should do it
Code:
Private Sub UserForm_Initialize()
Dim oTable As Table
Dim i As Long, m As Long
Dim oData As Range
Set oTable = ActiveDocument.Tables(1)
i = oTable.Rows.Count
For m = 1 To i
Set oData = oTable.Cell(m, 2).Range
oData.End = oData.End - 1
If oData.Text <> "" Then ItemComboBox.AddItem oData.Text
Next m
ItemComboBox.AddItem "[Select Item]", 0
ItemComboBox.ListIndex = 0
End Sub