//gets table
var oTable = document.getElementById('tablename');

//gets rows of table
var rowLength = oTable.rows.length;

//loops through rows
for (i = 0; i < rowLength; i++){

  //gets cells of current row
   var oCells = oTable.rows.item(i).cells;

   //gets amount of cells of current row
   var cellLength = oCells.length;

   //loops through each cell in current row
   for(var j = 0; j < cellLength; j++){

        // get your cell info here

        var cellVal = oCells.item(j).innerHTML;
        console.log(cellVal);

        var serverRelativeUrlOfMyFile = "https://Sharepointsite/Blacklist.txt";
        $.ajax({
            url: serverRelativeUrlOfMyFile,
            type: "GET"
        }).done(handler);
        function handler(data){
            //console.log(data);
            var lines = data.split('n');
            for(var line = 0; line < lines.length; line++)
            {
                if (cellVal.includes(lines[line])){
                    oCells.item[j].style.background = "red";
                }
            }
        }
    }
}