Hi,
The first thing: if these strings take up more than one line, you should know that in ABAP it is not permitted. I copied your code and got "Literals that take up more than one line not permitted."
You may want to split them and concatenate or, if you are in a more recent SAP release, you can concatenate using &&. Like below:
APPEND '<script type="text/javascript">$(".col-sm-3")' && '.hover(function(e){title = $(this).attr("title");$("#desc").' && 'html("<span>" + title + "</span>");$(this).removeAttr("title");},' && 'function(e){$("span", "#desc").html("DESCRIPTION");' TO lt_html.
Splitting the string up can also help you pinpoint where the error is, if there is one.
Hope this helps.