[Browsable(false)]
public XRTableCellCollection Cells { get; }

<Browsable(False)>
Public ReadOnly Property Cells As XRTableCellCollection

using DevExpress.XtraReports.UI;
// ...
// Create a report.
XtraReport report = new XtraReport();

// Create a detail band and add it to the report.
DetailBand detailBand = new DetailBand();
report.Bands.Add(detailBand);

// Create a table.
XRTable table = new XRTable();

// Add rows and columns to the table.
int numRows = 10;
int numCols = 20;

table.BeginInit();

for (int i = 0; i < numRows; i++) {
    XRTableRow row = new XRTableRow();
    table.Rows.Add(row);

    for (int j = 0; j < numCols; j++) {
        XRTableCell cell = new XRTableCell();
        table.Rows[i].Cells.Add(cell);
    }
}

// Set table size.
table.HeightF = 50;
table.WidthF = 500;

table.EndInit();

// Add the table to the detail band and adjust the band height.
detailBand.Controls.Add(table);
detailBand.HeightF = table.HeightF;

Imports DevExpress.XtraReports.UI
' ...
            ' Create a report.
            Dim report As New XtraReport()

            ' Create a detail band and add it to the report.
            Dim detailBand As New DetailBand()
            report.Bands.Add(detailBand)

            ' Create a table.
            Dim table As New XRTable()

            ' Add rows and columns to the table.
            Dim numRows As Integer = 10
            Dim numCols As Integer = 20

            table.BeginInit()

            For i As Integer = 0 To numRows - 1
                Dim row As New XRTableRow()
                table.Rows.Add(row)

                For j As Integer = 0 To numCols - 1
                    Dim cell As New XRTableCell()
                    table.Rows(i).Cells.Add(cell)
                Next j
            Next i

            ' Set table size.
            table.HeightF = 50
            table.WidthF = 500

            table.EndInit()

            ' Add the table to the detail band and adjust the band height.
            detailBand.Controls.Add(table)
            detailBand.HeightF = table.HeightF

float totalWidth = 0;
foreach(XRTableCell dc in table.Key.Rows[0].Cells) {
    float newWidth = cellColumnWidthCollection[dc];

Dim totalWidth As Single = 0
For Each dc As XRTableCell In table.Key.Rows(0).Cells
    Dim newWidth As Single = cellColumnWidthCollection(dc)