Visual FoxPro's native CHAR
type only allows up to about 255 characters. What you're seeing is a FoxPro MEMO field, translated to a generic OLE equivalent.
A SQL Server VARCHAR(MAX) is the usual proper equivalent, assuming the MEMO is simply user-entered text in a western dialect and not a multi-linqual or data-blob variation.
Be aware that FoxPro does NOT speak UTF natively, so you may have code-page translation issues.