* Walmart, Home Depot post strong third quarter * October retail sales rise more than expected * Futures: Dow up 0.18%, S&P flat, Nasdaq down 0.07% (Adds comment, updates prices) By Ambar Warrick and Devik Jain Nov 16 (Reuters) - Wall Street indexes were set to open slightly higher on Tuesday as a strong holiday forecast from Walmart and a better-than-expected retail sales data boosted confidence in an economic recovery. With Americans starting their holiday shopping early to avoid empty shelves amid supply chain disruptions, retail sales rose more than expected in October, giving the economy a lift at the start of the fourth quarter. Walmart, the country's largest brick-and-mortar retailer, raised its annual sales and profit forecasts.