Sets the preferred width of the table and the units for said width.

public void SetPreferredWidth(double width, Units units)

Public Sub SetPreferredWidth(ByVal width As Double, ByVal units As Units)

The preferred width of the table.
MS Word equivalent: Table menu > Table Properties... > Table tab > Options... > dropdown after "Preferred width"

The units for the width.
For Units.Auto:
MS Word equivalent: Table menu > Table Properties... > Table tab > Options... > Preferred width
For Units.Percent, or Units.Twips:
MS Word equivalent: Table menu > Table Properties... > Table tab > Options... > Measure in

If units is something other than Units.Auto,Units.Percent, or Units.Twips.

// 50%
table.SetPreferredWidth(50, Units.Percent);
// or 2"
table.SetPreferredWidth(2880, Units.Twips);
// or auto fit
table.SetPreferredWidth(0,Units.Auto);

' 50%
table.SetPreferredWidth(50, Units.Percent)
' or 2"
table.SetPreferredWidth(2880, Units.Twips)
' or auto fit
table.SetPreferredWidth(0, Units.Auto)