Jyothirmayi,
did you create your hdbtable file on the project explorer? then you activated it, etc? was the data type of tabel1 in sync w the design time table on the system tab .. did you create it under your schema? were other developers involved?
anyways.. i can foresee an issue if more than one developer was involved in changing the structure of the table... if only one developer is doing these changes, then i do not know. please remove and re-create the table... one thing to know is that if you created a design time table and then altered its structure via sql then that may be the issue.. otherwise, try to stay on the design time object in the project explorer tab (either hdbtable or using hdbdd / CDS )
just curious, what version of HANA do you have? and is this on-prem or hcp system?
I may not have an answer but just wanted to learn more about the issue