You are confusing cell width with the maximum text value that can be stored
in a cell.

The maximum text value for a cell is 32,767 characters. Although the cell
width max is 256 characters, up to 1,024 display in a cell (assuming you
have wrapped text); all 32,767 are stored and will display in the formula
bar.

Look up the delprioritychar file type modifier to get around the embedded nl
characters in the memo fields.  I'm stuck importing a bunch of stuff from
Foxpro tables and they do the same thing.  One problem I had (once I
figured that part out) was that the Foxpro export format is somewhat
strange and I had all sorts of grief with it.  I have the add-on for Excel
that links the spreadsheet to Foxpro or Access so I use that to extract the
tables into Excel then save to a csv file - the Excel format is a lot more
useful and friendly for DB2 and you have a lot more control over the output
format. The direct-to-Excel import also handles the multi-line memo fields
so that hassle is avoided.  

One gotcha: both Access and Foxpro export date/time in weird ways,
especially if the columns contain nulls for date/time.  I use Excel to
reformat and the outputs and substitute true nulls where this occurs.  I
have yet to get any date+time (timestamp) data to port gracefully, though.