It's a humble meal, but please help yourself.
My presentation was poor.
お粗末 adds the honorific prefix お to 粗末 and is used humbly to describe one's own food or belongings, as in 'お粗末なものですが'.
Formed from the honorific prefix お (o-) and 粗末 (somatsu, 'crude, shoddy'). The exact historical derivation of 粗末 is uncertain, but it is conventionally associated with the kanji 粗 (coarse) and 末 (end, trivial).