diff --git a/excel.psgi b/excel.psgi
new file mode 100644
index 0000000..db29bb1
--- /dev/null
+++ b/excel.psgi
@@ -0,0 +1,109 @@
+use strict;
+use warnings;
+use Plack::Request;
+use Plack::Response;
+
+my $app = sub {
+    my $env = shift;
+    my $req = Plack::Request->new($env);
+
+    my $rows = 20;
+    my $cols = 10;
+
+    if ($req->method eq 'POST') {
+        my $params = $req->parameters;
+
+        my $output = "<h2>Submitted Data</h2><pre>";
+        for my $r (0 .. $rows - 1) {
+            for my $c (0 .. $cols - 1) {
+                my $key = "cell_${r}_${c}";
+                my $val = $params->{$key} // '';
+                $output .= sprintf("%-10s", $val);
+            }
+            $output .= "\n";
+        }
+        $output .= "</pre><a href='/'>Back</a>";
+
+        return [
+            200,
+            [ 'Content-Type' => 'text/html' ],
+            [$output]
+        ];
+    }
+
+    my $html = <<"HTML";
+<!DOCTYPE html>
+<html>
+<head>
+<title>PSGI Spreadsheet</title>
+<style>
+body {
+    font-family: sans-serif;
+}
+table {
+    border-collapse: collapse;
+}
+td, th {
+    border: 1px solid #ccc;
+    padding: 0;
+}
+input {
+    width: 80px;
+    border: none;
+    padding: 5px;
+    box-sizing: border-box;
+}
+th {
+    background: #eee;
+    text-align: center;
+}
+</style>
+</head>
+<body>
+
+<h1>Excel-like Grid</h1>
+
+<form method="POST">
+<table>
+<tr>
+    <th></th>
+HTML
+
+    # Column headers (A, B, C...)
+    for my $c (0 .. $cols - 1) {
+        my $label = chr(65 + $c);
+        $html .= "<th>$label</th>";
+    }
+    $html .= "</tr>";
+
+    # Rows
+    for my $r (0 .. $rows - 1) {
+        $html .= "<tr>";
+        $html .= "<th>" . ($r + 1) . "</th>";
+
+        for my $c (0 .. $cols - 1) {
+            my $name = "cell_${r}_${c}";
+            $html .= qq{<td><input name="$name" /></td>};
+        }
+
+        $html .= "</tr>";
+    }
+
+    $html .= <<"HTML";
+</table>
+<br>
+<button type="submit">Submit</button>
+</form>
+
+</body>
+</html>
+HTML
+
+    return [
+        200,
+        [ 'Content-Type' => 'text/html' ],
+        [$html]
+    ];
+};
+
+return $app;
