Code:
// Create a renderer and prepare (=layout) the document
MigraDoc.Rendering.DocumentRenderer docRenderer = new DocumentRenderer(doc);
docRenderer.PrepareDocument();
// Render the paragraph. You can render tables or shapes the same way.
docRenderer.RenderObject(gfx, XUnit.FromCentimeter(5), XUnit.FromCentimeter(10), "12cm", para);
doc = Your MigraDocument
para = Your table (in the example it is a paragraph, but it is same as with tables)
gfx = a graphics object from the PDFdocument you are creating
RenderObject places (renders) the migradoc object on the PDFdocument graphics object at the given x,y coordinates.
Hope it is more clear now...