The general idea is that you will need a process (maybe at the beginning node?) that uses the search step, and then stores the resulting expression in a state on the entity (such as MyTravelTime). Then, you can refer to that entity state in the travel time property of the time path.
travel time --> ModelEntity.MyTravelTime
Alternatively, you can refer to the row directly, if (for example), you have an integer state/property that indicates the entity type, and that corresponds to a row in the table:
travel time -> Table1[EntityType].TimeExpression (Here EntityType is a state or property that you've set somewhere else, and corresponds to the index of a row in the table).
Lastly, you can use the "set row" step in a process to link a row to an entity (or use the built-in Table row referencing properties on the source object). Then, you'd just need to reference the table column in the time expression:
travel time -> Table1.TimeExpression
-Adam