Try something along the lines of:
Code:
Dim strtxt As String, Tbl As Table, Rng As Range
strtxt = "SomeText"
Set Tbl = ActiveDocument.Tables(1)
Set Rng = Tbl.Cell(i, 3).Range
With Rng
.End = .End - 1
.Collapse wdCollapseEnd
.Text = strtxt
.Font.Bold = True
End With