This post contains material about slavery.
Some of the wills mentioning slavery are written by people in Britain who may never even visited the West Indies (why dirty their hands). Others are of residents there who are rather more involved.
For example, Alex Innes wrote a will at Spanish Town in Jamaica, in 1747.
"I give and devise unto Anne Innes my reputed natural Daughter by Jane Gregory (who is now in Scotland for her Education) the Sum of Fourteen Hundred Pounds Jamaica Money at her Age of Eighteen Years or day of Marriage which shall first happen And it is my Will that the Interest of the said Fourteen Hundred Pounds shall commence from and immediately after my death and shall be paid by my Executors for her Education and Maintenance untill her said Age or Marriage but if my said Daughter shall dye before her Age of Eighteen or Marriage"
Alex describes Anne's mother, Jane Gregory, as "a Free Mulatto Woman" and left her "the Sum of One Hundred Pounds Jamaica Money".
For his daughter Kitty:
"I give and devise unto Catherine Innes alias Kitty Innes my reputed natural Daughter by Mary Innes the Sum of Seven Hundred Pounds Jamaica Money […] the said Legacy to be paid unto my said natural Daughter Catherine Innes when She shall attain her Age of Eighteen Years of day of Marriage which shall first happen And it is my Will that the Interest of the said Legacy of Seven Hundred Pounds shall commence immediately from my death and shall be paid by my Executors for the Maintenance and Education of the said Catherine Innes in some part of Great Britain untill her Age or Marriage aforesaid"
Which sounds kinda OK. But then the following is what he says regarding Mary:
"It is my Will that my Executors hereinafter named or one of them do purchase the Freedom and Manumission of a Mulatto Woman named Mary Innes immediately after my death and for that purpose I will that any Sum not exceeding One Hundred and Twenty Pounds Jamaica Money be paid for such Manumission and from and immediately after such Manumission is Recorded I give and devise unto the said Mary Innes the Sum of Twenty Five Pounds Per Annum to commence from the time of the Record of the said Manumission and to be paid her Quarterly by my Executors for and during the Term of her natural Life"
Yeah I notice that you're not freeing her now, during your own lifetime...
And for comparison you're willing your married sister in Scotland £1000 which she doesn't sound like she really needs, so... 

Alex Innes also included enslaved people in his legacies to Jane Gregory and to Kitty & Mary Innes
, and unusually the will mentioned their names.
So we know that the people held under enslavement in his household included Rachael and her Children Abba Cuffee Quashec Whaucia and Aurilia, and two other women or girls named Diana & Molly. I wouldn't want them to be forgotten.