Actually impossible from the point of view of an import utility:

LOAD DATA [LOW_PRIORITY | CONCURRENT] [LOCAL] INFILE 'file_name.txt'
    [REPLACE | IGNORE]
    INTO TABLE tbl_name
    [FIELDS
        [TERMINATED BY '\t']
        [[OPTIONALLY] ENCLOSED BY '']
        [ESCAPED BY '\\' ]
    ]
    [LINES 
        [STARTING BY '']    
        [TERMINATED BY '\n']
    ]
    [IGNORE number LINES]
    [(col_name,...)]
[download]

Embedded newlines make it hard to define what represents a 'row'. Fortunately AFAIK you can't insert newlines into an Excel cell string as it triggers moving you to a new cell.

It is possible to enter newlines in an Excel cell, using ALT ENTER. The fields are then escaped in the CSV or TAB file using double quotes. So Hello\nWorld would look like this:

    "Hello\n
    World"
[download]

--
John.

I regularly work with Excel data with newlines inside a single cell. This is why CSV is preferrable over tab-delimited.

"Terry","Joan","Sourced from $BAR list
04/03: Send Info
09/04: Info sent","7 - Voting for turnip"

vs

Terry	Joan	Sourced from $BAR list\
04/03: Send info\
09/04: Info sent	7 - Voting for turnip