// Obtained at https://msdn.microsoft.com/en-us/library/office/ff820880.aspx

xlDown = -4121;    

// Get tne range we want to extract, in this case all rows of columns H-J.

// .End(xlDown) finds the last used cell in the indicated column

Range1 := Sheet.Range['H1', Sheet.Range['J1'].End[xlDown]];

Data := Range1.Value;