Unfortunately screen reader support isn't great at the moment, but using HTML instead of canvas is definitely going to make it easier for you to improve. I'd encourage you to download the free NVDA screen reader (https://www.nvaccess.org/download/) and compare DataGridXL with Excel, or Google Sheets with screen reader support enabled (Tools > Accessibility settings). Announcing the column, row and cell content as you navigate the sheet with the keyboard would be a great start. Google Sheets does this by updating the content of a visually hidden ARIA live region (https://developer.mozilla.org/en-US/docs/Web/Accessibility/A...) as you navigate.