diff --git a/BigTable.xls b/BigTable.xls
new file mode 100644
index 0000000..e7c7481
Binary files /dev/null and b/BigTable.xls differ
diff --git a/bigtable_test.go b/bigtable_test.go
new file mode 100644
index 0000000..356579a
--- /dev/null
+++ b/bigtable_test.go
@@ -0,0 +1,59 @@
+package xls
+
+import (
+	"fmt"
+	"testing"
+	"time"
+)
+
+func TestBigTable(t *testing.T) {
+	xlFile, err := Open("BigTable.xls", "utf-8")
+	if err != nil {
+		t.Fatalf("Cant open xls file: %s", err)
+	}
+
+	sheet := xlFile.GetSheet(0)
+	if sheet == nil {
+		t.Fatal("Cant get sheet")
+	}
+
+	cnt1 := 1
+	cnt2 := 10000
+	cnt3 := 20000
+	date1, _ := time.Parse("2006-01-02", "2015-01-01")
+	date2, _ := time.Parse("2006-01-02", "2016-01-01")
+	date3, _ := time.Parse("2006-01-02", "2017-01-01")
+
+	for i := 1; i <= 4999; i++ {
+		row := sheet.Row(i)
+		if row == nil {
+			continue
+		}
+
+		col2sample := fmt.Sprintf("%d от %s", cnt1, date1.Format("02.01.2006"))
+		col5sample := fmt.Sprintf("%d от %s", cnt2, date2.Format("02.01.2006"))
+		col8sample := fmt.Sprintf("%d от %s", cnt3, date3.Format("02.01.2006"))
+
+		col2 := row.Col(2)
+		col5 := row.Col(5)
+		col8 := row.Col(8)
+
+		if col2 != col2sample {
+			t.Fatalf("Row %d: col 2 val not eq base value: %s != %s", i, col2, col2sample)
+		}
+		if col5 != col5sample {
+			t.Fatalf("Row %d: col 5 val not eq base value: %s != %s", i, col5, col5sample)
+		}
+		if col8 != col8sample {
+			t.Fatalf("Row %d: col 8 val not eq base value: %s != %s", i, col8, col8sample)
+		}
+
+		cnt1++
+		cnt2++
+		cnt3++
+		date1 = date1.AddDate(0, 0, 1)
+		date2 = date2.AddDate(0, 0, 1)
+		date3 = date3.AddDate(0, 0, 1)
+
+	}
+}