When a block of data on a Prism data table is linked to another file (or to embedded data), the data in Prism is included in a box. The box is black if the linked data came from outside of Prism, red or green if the data were paste linked from a Prism results table, and blue if the data were paste linked from a Prism data table.

You cannot edit these values in the data table because they are linked to another source.

To unlink the data block, and allow editing, right click anywhere within the block of data, choose the Data Object command and then choose Unlink.