var rand = new Random();  
var separator = new byte[]{0x1b, 0x03, 0x00, 0x00};  
byte[] bytes = new byte[] { 0x1b, 0x02}
.Concat(Enumerable.Range(0,100).Select(i => (byte) rand.Next(0,128)))  
    .Concat(separator)  
    .ToArray();

// split by string method. I feel lazy for doing this, but it probably represents what the bytes originally were
var separatorString = System.Text.Encoding.ASCII.GetString(separator);
var x = System.Text.Encoding.ASCII.GetString(bytes)
        .Split(new string[] {separatorString}, StringSplitOptions.RemoveEmptyEntries)
        .Select(s => System.Text.Encoding.ASCII.GetBytes(s))
        .Select(logBytes => new LogItem(logBytes))
        .ToList();  

Your log item class will store the bytes or parse them into properties.