This JavaScript code allows you to download Steam purchase history table as a CSV file.

downloadSteamTransactionHistory.js

function downloadTableAsCSV(tableClass, filename) {
    // Get the table element using class name
    var table = document.getElementsByClassName(tableClass)[0];
    
    // Get all rows of the table
    var rows = table.getElementsByTagName("tr");
    
    // Create the CSV string
    var csvContent = "";
    for (var i = 0; i < rows.length; i++) {
        var row = rows[i];
        var cells = row.getElementsByTagName("td");
        
        // Add each cell data with comma separator
        for (var j = 0; j < cells.length; j++) {
            var cell = cells[j];
            var cellText = cell.innerText.replace(/"/g, '""').replace(/[\n\r,]/g, '');  // Escape double quotes, remove commas and line breaks for CSV
            csvContent += cellText + (j < cells.length - 1 ? "," : "\n");
        }
    }
    
    // Create a downloadable blob object
    var blob = new Blob([csvContent], { type: 'text/csv;charset=utf-8' });
    
    // Create a downloadable link
    var link = document.createElement("a");
    link.href = URL.createObjectURL(blob);
    link.download = filename || 'table.csv';
    
    // Simulate a click to trigger download
    link.click();
}

// Usage
var tableClass = "wallet_history_table";
var filename = "wallet_history.csv";
downloadTableAsCSV(tableClass, filename);