A test that we tried against artwork. Sort of works. Abandoned though.

Aspose.FindTables.cs

static void Main(string[] args)
{
    SetLicense();

    var path = Path.Combine(Environment.CurrentDirectory, "artwork1.pdf");
    using (var doc = new Document(path))
    {
        var tableOptions = new TextSearchOptions(false)
        {
            IgnoreShadowText = true,
            SearchForTextRelatedGraphics = false,
            UseFontEngineEncoding = false
        };
        var tableAbsorber = new TableAbsorber(tableOptions);

        Console.WriteLine("Starting the TableAbsorber");

        var page = doc.Pages.First();
        tableAbsorber.Visit(page);

        Console.WriteLine("Done with the TableAbsorber");

        var tables = tableAbsorber.TableList
            .Where(x => x.Rectangle.Width < 100)
            .Where(x => x.Rectangle.Height > 100);

        Console.WriteLine($"There are {tables.Count()} tables out of {tableAbsorber.TableList.Count()}.");
        Console.Read();

        var index = 0;

        foreach (var table in tables)
        {
            Console.WriteLine($"{++index} of {tables.Count()}");
            Console.WriteLine($"{table.Rectangle.Width} by {table.Rectangle.Height}");
            DrawRectangleOnPage(table.Rectangle, page);

            var text = ExtractText(table.Rectangle, page);
            if (!string.IsNullOrEmpty(text))
            {
                var search = Regex.Replace(text.ToLower(), "[^a-z0-9:]", string.Empty);
                Console.WriteLine(search);
            }
            else
            {
                Console.WriteLine("No text.");
            }
        }

        SaveDoc(doc);
    }
}

private static string ExtractText(Aspose.Pdf.Rectangle rectangle, Page page)
{
    var options = new TextSearchOptions(rectangle)
    {
        LimitToPageBounds = true,
        IsRegularExpressionUsed = false,
        IgnoreShadowText = false,
    };
    var absorber = new TextAbsorber(options);
    page.Accept(absorber);
    return absorber.Text;
}

private static void DrawRectangleOnPage(Rectangle rectangle, Page page)
{
    page.Contents.Add(new Aspose.Pdf.Operators.GSave());
    page.Contents.Add(new Aspose.Pdf.Operators.ConcatenateMatrix(1, 0, 0, 1, 0, 0));
    page.Contents.Add(new Aspose.Pdf.Operators.SetRGBColorStroke(0, 1, 0));
    page.Contents.Add(new Aspose.Pdf.Operators.SetLineWidth(2));
    page.Contents.Add(
        new Aspose.Pdf.Operators.Re(rectangle.LLX,
            rectangle.LLY,
            rectangle.Width,
            rectangle.Height));
    page.Contents.Add(new Aspose.Pdf.Operators.ClosePathStroke());
    page.Contents.Add(new Aspose.Pdf.Operators.GRestore());
}

private static void DrawPolygonOnPage(Point[] polygon, Page page)
{
    page.Contents.Add(new Aspose.Pdf.Operators.GSave());
    page.Contents.Add(new Aspose.Pdf.Operators.ConcatenateMatrix(1, 0, 0, 1, 0, 0));
    page.Contents.Add(new Aspose.Pdf.Operators.SetRGBColorStroke(0, 0, 1));
    page.Contents.Add(new Aspose.Pdf.Operators.SetLineWidth(1));
    page.Contents.Add(new Aspose.Pdf.Operators.MoveTo(polygon[0].X, polygon[0].Y));
    for (var i = 1; i < polygon.Length; i++)
    {
        page.Contents.Add(new Aspose.Pdf.Operators.LineTo(polygon[i].X, polygon[i].Y));
    }
    page.Contents.Add(new Aspose.Pdf.Operators.LineTo(polygon[0].X, polygon[0].Y));
    page.Contents.Add(new Aspose.Pdf.Operators.ClosePathStroke());
    page.Contents.Add(new Aspose.Pdf.Operators.GRestore());
}

private static void SetLicense()
{
    var license = new Aspose.Pdf.License();
    license.SetLicense("Aspose.Pdf.lic");
}