var tableEl, rowEl, cellEl;
var numRows = 10;
var numCells = 5;

tableEl = document.createElement("TABLE");
tableEl = document.body.appendChild(tableEl);
for (i = 0; i < numRows; i++) {
    rowEl = document.createElement("TR");  
    for (j = 0; j < numCells;j++) {
        cellEl = document.createElement("TD");
        cellEl.appendChild(document.createTextNode("[row "+i+" cell "+j+ "]"));
        rowEl.appendChild(cellEl);
    }
    tableEl.appendChild(rowEl);
}